HVAC guys, need some help. (1 Viewer)

[parasaurolophus]

So my furnace has me quite confused(Payne 90%).

Background... Yesterday it stopped working. Gave me a code 31. Was very busy so I called the hvac company i use. They said they would call me back and let me know when they were coming. 3 hours later i hadnt heard yet so i call back. No answer. So i decided to check it out myself as it was getting cold in my house. 

Disconnect condensate trap hose and half a gallon of water comes pouring out. Trap obviously clogged. Remove trap, clean out, put back on, furnace fires up no problem. Phone rings, it is the tech in my driveway. 

Since the guy was there anyway they offered me a discount on getting a tune up. I agree. Tech gets to work and eventually comes upstairs to show me the igniter is just outside reco'd resistance range, but still working. Offers to replace for free since it is a common igniter and he already has it out. I of course agree. Furnace fires up no problem right in front of me when he is done, he puts it back together and is on his way. House gets warmed up. I keep old igniter. I leave for a couple hours and come home to a cooler house than i expected. 

Code 34. (Igniter, flame sensor, gas pressure.)

Call the company, they cant get somebody back out. So i get to work troubleshooting. Put the old igniter back in, wont fire up. Anyway on a whim, i take the burner box cover off, since that was how i saw it fire up when tech was here. 

Fires up no problem. Burner box cover on, nope.  Off yes. Repeat like ten more times. 100% certain that it will fire and run as long as i want it and as many cycles as i want with burner box cover off. 

Logical injtial conclusion would be it creates a vacuum and flips pressure switch and air intake must be blocked. 

PVC is clear though as far as i can tell(put a blower on it just to be safe) but even if still blocked that should NOT give a code 34. So pretty convinced this is not a problem. 

Obviously have gas pressure and igniter obviously works.

Any ideas?

 

[Sullie]

I'm just an IT guy, I don't know a damn thing but I do find furnaces interesting and satisfying to fix.  I found an interesting thread, same furnace make, code 34 error message here.  Skimming through the thread, one guy states that code 34 (in this specific situation) means the following :

Code 34 is a secondary code... "failed to light in three attempts".
You would get a different code.... like 14.... before that.
You need to watch the entire process until it fails.

Link to installation manual - lots of good information contained within that pdf, testing specific functions, etc. definitely worth a browse.   Hope that's a little helpful.

 

[ChiefD]

So my furnace has me quite confused(Payne 90%).

Background... Yesterday it stopped working. Gave me a code 31. Was very busy so I called the hvac company i use. They said they would call me back and let me know when they were coming. 3 hours later i hadnt heard yet so i call back. No answer. So i decided to check it out myself as it was getting cold in my house. 

Disconnect condensate trap hose and half a gallon of water comes pouring out. Trap obviously clogged. Remove trap, clean out, put back on, furnace fires up no problem. Phone rings, it is the tech in my driveway. 

Since the guy was there anyway they offered me a discount on getting a tune up. I agree. Tech gets to work and eventually comes upstairs to show me the igniter is just outside reco'd resistance range, but still working. Offers to replace for free since it is a common igniter and he already has it out. I of course agree. Furnace fires up no problem right in front of me when he is done, he puts it back together and is on his way. House gets warmed up. I keep old igniter. I leave for a couple hours and come home to a cooler house than i expected. 

Code 34. (Igniter, flame sensor, gas pressure.)

Call the company, they cant get somebody back out. So i get to work troubleshooting. Put the old igniter back in, wont fire up. Anyway on a whim, i take the burner box cover off, since that was how i saw it fire up when tech was here. 

Fires up no problem. Burner box cover on, nope.  Off yes. Repeat like ten more times. 100% certain that it will fire and run as long as i want it and as many cycles as i want with burner box cover off. 

Logical injtial conclusion would be it creates a vacuum and flips pressure switch and air intake must be blocked. 

PVC is clear though as far as i can tell(put a blower on it just to be safe) but even if still blocked that should NOT give a code 34. So pretty convinced this is not a problem. 

Obviously have gas pressure and igniter obviously works.

Any ideas?

One of my techs had this exact problem yesterday on a Bryant furnace. (Payne made by the same company).

Water in the inducer motor and pressure switch hoses. Got it all cleaned out and unit would only fire with the furnace door off. 

Tech finally figured out one of the pressure switch hoses was pinched when he put it back together. So check all your hoses, connections, etc to make sure nothing is pinched. 

And btw, that problem you are experiencing is a pain in my ### about 4 times a winter. We run across these and some of them are just a mystery to try and figure out.

 

[parasaurolophus]

One of my techs had this exact problem yesterday on a Bryant furnace. (Payne made by the same company).

Water in the inducer motor and pressure switch hoses. Got it all cleaned out and unit would only fire with the furnace door off. 

Tech finally figured out one of the pressure switch hoses was pinched when he put it back together. So check all your hoses, connections, etc to make sure nothing is pinched. 

And btw, that problem you are experiencing is a pain in my ### about 4 times a winter. We run across these and some of them are just a mystery to try and figure out.

I can blow through every vacuum hose no problem. Took them all off. 

Could the igniter just be in a bad position? And the cover being off effects the gas flow just enough that it lights because if that? 

I think i have ruled out pressure switches because if i put the burner cover on once it is burning, it will run a full cycle and wont flip code 34 again until it tries to fire up again. 

 

[ChiefD]

I can blow through every vacuum hose no problem. Took them all off. 

Could the igniter just be in a bad position? And the cover being off effects the gas flow just enough that it lights because if that? 

I think i have ruled out pressure switches because if i put the burner cover on once it is burning, it will run a full cycle and wont flip code 34 again until it tries to fire up again. 

I don't think it's the igniter. If it will work with the door off it is usually an obstruction somewhere. 

Like I said earlier, this type of furnace is a pain. I've had 3 of these in the last year - same furnace as yours that have the same issue. They work great for 3 or 4 years (or more even) and then all of a sudden it has the issue you are seeing.

On one of them we re-piped the intake and exhaust all the way out and it solved it. 

The one I spoke about above with the pinched hose is still having issues. We are going back today. 

 

[parasaurolophus]

I don't think it's the igniter. If it will work with the door off it is usually an obstruction somewhere. 

Like I said earlier, this type of furnace is a pain. I've had 3 of these in the last year - same furnace as yours that have the same issue. They work great for 3 or 4 years (or more even) and then all of a sudden it has the issue you are seeing.

On one of them we re-piped the intake and exhaust all the way out and it solved it. 

The one I spoke about above with the pinched hose is still having issues. We are going back today. 

Why is the gas valve connected to the pressure switch? is that common? 

Here is the valve that is on my furnace. I have a brass nipple coming out of the spot that looks like a copper rivet in the second picture. That brass nipple is teed into the pressure switch. 

 

[ChiefD]

Why is the gas valve connected to the pressure switch? is that common? 

Here is the valve that is on my furnace. I have a brass nipple coming out of the spot that looks like a copper rivet in the second picture. That brass nipple is teed into the pressure switch. 

Don't know. I'm not a tech: I'm the guy who manages our techs. But I know enough of the basics to try and help folks. Plus I can let you know if you are getting the run around or not.

For something like this, have that company come back out. There are so many possibilities for this repair you'll drive yourself nuts trying to chase it down.

 

[matttyl]

Have an HVAC question myself, and sorry that I can't help the OP.

I have two stage heat - first stage is heat pump, second is electric (which is damn expensive as I'm sure you know).  My "smart" thermostats, when they kick on, and the actual temperature in the room and the set temperature are 2_ degrees apart will fire up both at the same time to heat things up faster.  Is there any way to shut this feature off, unless the outside temperature is too low for the heat pumps?

For example - I turn (or rather have the smart thermostat turn) the heat down overnight while sleeping down to like 60.  It have it set to "wake" at like 6:30 and to be 65 or so.  If it's actually 63 or below in the house when that happens, it fires up both the heat pump and the electric heat - and thus my power bills are outrageous in the winter months.  Is there any way to set it to only kick on electric heat if the outside temp is under 30 or so (meaning too low for just the heat pump)?

Thanks.

 

[ChiefD]

Have an HVAC question myself, and sorry that I can't help the OP.

I have two stage heat - first stage is heat pump, second is electric (which is damn expensive as I'm sure you know).  My "smart" thermostats, when they kick on, and the actual temperature in the room and the set temperature are 2_ degrees apart will fire up both at the same time to heat things up faster.  Is there any way to shut this feature off, unless the outside temperature is too low for the heat pumps?

For example - I turn (or rather have the smart thermostat turn) the heat down overnight while sleeping down to like 60.  It have it set to "wake" at like 6:30 and to be 65 or so.  If it's actually 63 or below in the house when that happens, it fires up both the heat pump and the electric heat - and thus my power bills are outrageous in the winter months.  Is there any way to set it to only kick on electric heat if the outside temp is under 30 or so (meaning too low for just the heat pump)?

Thanks.

Your thermostat should be able to do this automatically. So something isn't set right.

Usually it's based on time - if stage 1 won't satisfy the thermostat in X amount of time, stage 2 would then kick on the second stage heat.

What stat do you have?

 

[matttyl]

Your thermostat should be able to do this automatically. So something isn't set right.

Usually it's based on time - if stage 1 won't satisfy the thermostat in X amount of time, stage 2 would then kick on the second stage heat.

What stat do you have?

It's a honeywell smart wifi touchscreen deal.  There are a few different models, but I think I have this one.

From what I've read, it has a 2 degree rule.  If increase in temperature is 2 or more degrees, it will use both until the desired temperature is reached, once there it will use just the heat pump. 

 

[ChiefD]

It's a honeywell smart wifi touchscreen deal.  There are a few different models, but I think I have this one.

From what I've read, it has a 2 degree rule.  If increase in temperature is 2 or more degrees, it will use both until the desired temperature is reached, once there it will use just the heat pump. 

Based on that link, if you scroll down there is a manual.

You'll have to see how it is set up in Heat Pump mode.  But typically a heat pump is always the first source of heat until it cannot satisfy the stat in a predetermined set of time. Then your electric heat will kick in. 

Did you install the stat yourself?

 

[matttyl]

Based on that link, if you scroll down there is a manual.

You'll have to see how it is set up in Heat Pump mode.  But typically a heat pump is always the first source of heat until it cannot satisfy the stat in a predetermined set of time. Then your electric heat will kick in. 

Did you install the stat yourself?

Yes I did.  Both the install of the wiring, as well as the programing of the unit itself.  You tell the unit that it has 2 heat sources, and it has this 2 degree rule to heat up the home faster.  That's all well and good if it's 15 outside, but if it's 40 in the morning, just use heatpump only.  Just trying to find out how to do that.

 

[parasaurolophus]

Problem solved, I think. 

Came across this bulletin for my furnace model.

Note: If the ignitor is installed through the bottom of the burner box, ensure that there is not a gap between the ceramic of the ignitor and the ignitor gasket. A gap in this area can cause light –off issues or burner pulsations

When I put the old igniter back in, I noticed that the gasket was crap. It was ripped and the part that was stuck to the burner box was shifted a bit. So I peeled it off and reattached it using some high temp adhesive. I also reattached the part that attaches to the removable piece. Verified that the igniter had gasket in contact all the way around the ceramic. and then tightened the igniter into that insert. Then reinserted it back into the furnace. Plugged it in, put the cover back on the box and she fired right up. It has now cycled through a ton of times without issue. 

Tech showed up right as I am putting the burner cover back on. Told him about the service bulletin. He of course scoffed at it. "I've never heard of that problem before." Showed him the bulletin. He seemed to be the kind of guy that hates the internet and doesn't trust it. He was wearing croakies for his glasses so that should tell you something.  

He decided to take the condensate trap off again and run water through it. Even though I had already done so yesterday and so did the other guy from yesterday and of course the furnace fired up right in front of him. He told me they are the biggest problem on this model and he has already cleaned out four of them the last two days and they can be "finicky".

I thought the whole interaction was kind of funny and I would love to see what he wrote for his repair notes. 

"Cleaned condensate trap. Solved issues"

 

[matttyl]

Based on that link, if you scroll down there is a manual.

You'll have to see how it is set up in Heat Pump mode.  But typically a heat pump is always the first source of heat until it cannot satisfy the stat in a predetermined set of time. Then your electric heat will kick in. 

Did you install the stat yourself?

Looked into this a bit more yesterday, and even called Honeywell (and did a "chat" and was given the same answer).  Apparently, "it's a feature, not a bug" kinda thing.  If you turn down your thermostat at night or midday if you're away, and then have it heat up when you "wake" or when you "return" home, and the setpoint is 2+ degrees more than the current temperature, it will fire up not only the heat pump but also the electric heating elements to heat up the home faster.  This happens no matter what the temperature is outside - it could be 50 degrees outside, and it will still augment the heat pump with electric heat.  So dumb if you ask me. 

So I was given to possible solutions, neither are good.

#1 - reprogram the thermostats (I have two, one upstairs, one down) to tell it you only have the one heat source.  Do it again later in the winter when you actually need the auxiliary/backup heat.  This is fine for now so long as the outside temperature doesn't get below say 25, which it's not forecasted to.  But I'll have to remember to reprogram it again later telling it I do have a backup heat source when it does get colder.  I'm unsure if it will still use "emergency heat" or not if I only tell it I have the one source.

or

#2 - only set the temperature back by a single degree (or not at all).  This way the setpoint and the actual temperature will never be more than a single degree.  Seems very counter intuitive for a "smart thermostat" which is suppose to save you money.

 

[ChiefD]

Problem solved, I think. 

Came across this bulletin for my furnace model.

When I put the old igniter back in, I noticed that the gasket was crap. It was ripped and the part that was stuck to the burner box was shifted a bit. So I peeled it off and reattached it using some high temp adhesive. I also reattached the part that attaches to the removable piece. Verified that the igniter had gasket in contact all the way around the ceramic. and then tightened the igniter into that insert. Then reinserted it back into the furnace. Plugged it in, put the cover back on the box and she fired right up. It has now cycled through a ton of times without issue. 

Tech showed up right as I am putting the burner cover back on. Told him about the service bulletin. He of course scoffed at it. "I've never heard of that problem before." Showed him the bulletin. He seemed to be the kind of guy that hates the internet and doesn't trust it. He was wearing croakies for his glasses so that should tell you something.  

He decided to take the condensate trap off again and run water through it. Even though I had already done so yesterday and so did the other guy from yesterday and of course the furnace fired up right in front of him. He told me they are the biggest problem on this model and he has already cleaned out four of them the last two days and they can be "finicky".

I thought the whole interaction was kind of funny and I would love to see what he wrote for his repair notes. 

"Cleaned condensate trap. Solved issues"

That bulletin is for heat exchanger inspections, just an FYI, so not really related to your issue. But if that small gap would be enough to cause a vacuum issue, then good job.

I'll ask one of my techs what he thinks about it and report back. 

 

[parasaurolophus]

That bulletin is for heat exchanger inspections, just an FYI, so not really related to your issue. But if that small gap would be enough to cause a vacuum issue, then good job.

I'll ask one of my techs what he thinks about it and report back. 

Well came across the bulletin because of this thread where somebody was having a similar problem. An early post from somebody that appears to be a tech suggested checking the gasket. That didnt solve his problem but sure seems to have solved mine.  

The note in that bulletin was fairly unambiguous.   

Also logically speaking if there was a gap there(which there was because when igniter was glowing you could see it from underneath burner box), when the burner cover is on that would create an updraft right by the igniter. 

 

[ChiefD]

Well came across the bulletin because of this thread where somebody was having a similar problem. An early post from somebody that appears to be a tech suggested checking the gasket. That didnt solve his problem but sure seems to have solved mine.  

The note in that bulletin was fairly unambiguous.   

Also logically speaking if there was a gap there(which there was because when igniter was glowing you could see it from underneath burner box), when the burner cover is on that would create an updraft right by the igniter. 

Yeah, that's a good find if it works.  Let me know if yours stays online. I know sometimes a tech clears out all the traps and the issue comes back a day or two later.

The case I was talking about above is still rearing it's ugly head. I will suggest your find and see if thats an option.

 

[ChiefD]

Looked into this a bit more yesterday, and even called Honeywell (and did a "chat" and was given the same answer).  Apparently, "it's a feature, not a bug" kinda thing.  If you turn down your thermostat at night or midday if you're away, and then have it heat up when you "wake" or when you "return" home, and the setpoint is 2+ degrees more than the current temperature, it will fire up not only the heat pump but also the electric heating elements to heat up the home faster.  This happens no matter what the temperature is outside - it could be 50 degrees outside, and it will still augment the heat pump with electric heat.  So dumb if you ask me. 

So I was given to possible solutions, neither are good.

#1 - reprogram the thermostats (I have two, one upstairs, one down) to tell it you only have the one heat source.  Do it again later in the winter when you actually need the auxiliary/backup heat.  This is fine for now so long as the outside temperature doesn't get below say 25, which it's not forecasted to.  But I'll have to remember to reprogram it again later telling it I do have a backup heat source when it does get colder.  I'm unsure if it will still use "emergency heat" or not if I only tell it I have the one source.

or

#2 - only set the temperature back by a single degree (or not at all).  This way the setpoint and the actual temperature will never be more than a single degree.  Seems very counter intuitive for a "smart thermostat" which is suppose to save you money.

This just makes no sense to me. It totally defeats the purpose for what two stage heat is designed for. Especially with a heat pump. I think their tech support was wrong.

Have you double checked your wiring?

 

[matttyl]

This just makes no sense to me. It totally defeats the purpose for what two stage heat is designed for. Especially with a heat pump. I think their tech support was wrong.

Have you double checked your wiring?

I've come across quite a few articles that talk about this "feature" / situation.  It's apparently a thing.  Certain thermostats can deal with it, but most don't.  If the increase in temp is 2+ degrees, it will use both heat sources to heat it up as quickly as possible. 

Here's one little article I found when googling about if turning down a thermostat with a heat pump makes sense - https://riverreporter.com/stories/leave-that-heat-pump-thermostat-alone-in-winter,17642?

Thinking I'll just set both to 65 or so full time.  Maybe down one degree middle of the day and overnight.  If I want it warmer than that, I'll just do it manually (of via the app).

And yes, wiring is all good.  There's nothing "wrong" with the install, it's working the way it was designed to - unfortunately. 

 

[matttyl]

This just makes no sense to me. It totally defeats the purpose for what two stage heat is designed for. Especially with a heat pump. I think their tech support was wrong.

Have you double checked your wiring?

Actually, here's something from the US Department of Energy!

"Limitations for Homes With Heat Pumps, Electric Resistance Heating, Steam Heat, and Radiant Floor Heating

Programmable thermostats are generally not recommended for heat pumps. In its cooling mode, a heat pump operates like an air conditioner, so turning up the thermostat (either manually or with a programmable thermostat) will save energy and money. But when a heat pump is in its heating mode, setting back its thermostat can cause the unit to operate inefficiently, thereby canceling out any savings achieved by lowering the temperature setting. Maintaining a moderate setting is the most cost-effective practice. Recently, however, some companies have begun selling specially designed programmable thermostats for heat pumps, which make setting back the thermostat cost-effective. These thermostats typically use special algorithms to minimize the use of backup electric resistance heat systems."

 

[ChiefD]

Actually, here's something from the US Department of Energy!

"Limitations for Homes With Heat Pumps, Electric Resistance Heating, Steam Heat, and Radiant Floor Heating

Programmable thermostats are generally not recommended for heat pumps. In its cooling mode, a heat pump operates like an air conditioner, so turning up the thermostat (either manually or with a programmable thermostat) will save energy and money. But when a heat pump is in its heating mode, setting back its thermostat can cause the unit to operate inefficiently, thereby canceling out any savings achieved by lowering the temperature setting. Maintaining a moderate setting is the most cost-effective practice. Recently, however, some companies have begun selling specially designed programmable thermostats for heat pumps, which make setting back the thermostat cost-effective. These thermostats typically use special algorithms to minimize the use of backup electric resistance heat systems."

Sure, I agree with that, but that doesn't address your issue. It's never a good idea to set your thermostat back more than a few degrees in a programmable situation for the reason above. 

But, that doesn't mean squat for what you are experiencing.

Your heat pump should provide 100% of your heat until your outdoor temperature hits about 32 degrees or so. At that point a heat pump has a harder time hitting the set temp on your thermostat. At that point (after a certain amount of time), your secondary heat would then kick on.

If both of yours are kicking on simultaneously, your system is hooked up wrong and/or set up wrong. 

 

[matttyl]

Sure, I agree with that, but that doesn't address your issue. It's never a good idea to set your thermostat back more than a few degrees in a programmable situation for the reason above. 

But, that doesn't mean squat for what you are experiencing.

Your heat pump should provide 100% of your heat until your outdoor temperature hits about 32 degrees or so. At that point a heat pump has a harder time hitting the set temp on your thermostat. At that point (after a certain amount of time), your secondary heat would then kick on.

If both of yours are kicking on simultaneously, your system is hooked up wrong and/or set up wrong.

Only happens when there is a 2+ degree difference.  What they are talking about is exactly my issue. 

If I set the thermostat to say 65 100% of the time, then my heat pump will be providing 100% of my heat until it gets below freezing outside.  If I set it back and it kicks on and needs to heat up 2+ degrees, it will simultaneously use both until it's within a single degree, then see if the heat pump alone can keep it there of if it still needs help.

 

[ChiefD]

Only happens when there is a 2+ degree difference.  What they are talking about is exactly my issue. 

If I set the thermostat to say 65 100% of the time, then my heat pump will be providing 100% of my heat until it gets below freezing outside.  If I set it back and it kicks on and needs to heat up 2+ degrees, it will simultaneously use both until it's within a single degree, then see if the heat pump alone can keep it there of if it still needs help.

Gotcha. Makes sense then if this is happening when it gets below freezing. 

 

[matttyl]

Gotcha. Makes sense then if this is happening when it gets below freezing. 

and I'm fine with that.  Just don't want it to happen when it's above freezing outside.  If I set it back to say 62 overnight, and have it kick up to 65 by 7am, it will use both sources until it hits 64. 

 

[ChiefD]

@parasaurolophus - you still going strong on that furnace?

I've since seen a different service bulletin for this issue, and there are a couple other possible solutions if you are still having issues.  

 

[parasaurolophus]

@parasaurolophus - you still going strong on that furnace?

I've since seen a different service bulletin for this issue, and there are a couple other possible solutions if you are still having issues.  

Yep going strong!

 

[coyote5]

@ChiefD

Bumping this for a HVAC question for everyone but I think Chief specifically is in this industry.

My system is 15 years old, never had maintenance performed on it.  I was planning to have that done next week, but one of my HVAC friends suggested I may not want to open that can of worms.  He says after all this time, maintenance may cause other problems to pop up.  I just need this system to last about 2 more years.  Should I skip the maintenance at this point?

Side note and additional question - I have an aprilaire HRV system that was starting to make some sort of rattling noise so I just turned it off, it's also never had maintenance.   Should I just leave it off and ignore it?  How much efficiency am I losing by not having it running?

Thanks!

 

[ChiefD]

@ChiefD

Bumping this for a HVAC question for everyone but I think Chief specifically is in this industry.

My system is 15 years old, never had maintenance performed on it.  I was planning to have that done next week, but one of my HVAC friends suggested I may not want to open that can of worms.  He says after all this time, maintenance may cause other problems to pop up.  I just need this system to last about 2 more years.  Should I skip the maintenance at this point?

Side note and additional question - I have an aprilaire HRV system that was starting to make some sort of rattling noise so I just turned it off, it's also never had maintenance.   Should I just leave it off and ignore it?  How much efficiency am I losing by not having it running?

Thanks!

Yeah, I would tend to agree with your friend. After 15 years sometimes when you opening up valves and such things could happen. Your best bet would be to take a garden hose and just make sure you spray your outdoor unit once a season. And - change your filter of course on a regular basis.

As a point of reference, my air conditioner at my house was there when I bought it ten years ago. It's a 1989 unit. I have never serviced it for the same reason. I wash it every year and change my filters. I'll replace it when it goes down.

As for the HRV, not sure. We don't do those for the most part, but I know they are designed to bring fresh air into a home to combat a tighter home. Older homes breathe plenty of air generally, but newer homes have a tighter envelope so an HRV will exchange the air with the outdoors several times a day. So not running it can impact the air quality in your home and potentially lead to issues there. I would probably have that looked at.

 

[coyote5]

Yeah, I would tend to agree with your friend. After 15 years sometimes when you opening up valves and such things could happen. Your best bet would be to take a garden hose and just make sure you spray your outdoor unit once a season. And - change your filter of course on a regular basis.

As a point of reference, my air conditioner at my house was there when I bought it ten years ago. It's a 1989 unit. I have never serviced it for the same reason. I wash it every year and change my filters. I'll replace it when it goes down.

As for the HRV, not sure. We don't do those for the most part, but I know they are designed to bring fresh air into a home to combat a tighter home. Older homes breathe plenty of air generally, but newer homes have a tighter envelope so an HRV will exchange the air with the outdoors several times a day. So not running it can impact the air quality in your home and potentially lead to issues there. I would probably have that looked at.

Thanks, are you saying my air con unit has a filter that should be changed, or are you referring to the furnace filter?   

 

[ChiefD]

Thanks, are you saying my air con unit has a filter that should be changed, or are you referring to the furnace filter?   

No - you should just have a furnace filter.