HVAC experts please help!

[Wayne 962]

Originally Posted by dad911

AC also? Evaporator coil dirty? Buildup on the squirrel cage?

Just heater - no dust on the squirrel cage...

-Wayne

[black73]

Originally Posted by cabmando

He hasn't reached Bezos/Gates status yet I don't think. ....

Yeah, I know. I'm just jealous because I don't have my own museum.

[cabmandone]

Originally Posted by black73

Yeah, I know. I'm just jealous because I don't have my own museum.

I know! I'm thinking a "consulting fee" might be in order.

[Wayne 962]

Originally Posted by cabmando

http://www.graycoolingman.com/uploads/1/0/6/6/10667336/58mvp-_2_stage_variable_speed_troubleshoot_guide.pdf
Open the troubleshooting guide and go to page 13 for Fault code 12. You can scroll from there to find the fault code and the troubleshooting steps recommended for fixing the issue.

You mention you used test mode. I believe this makes the system go through the stages of operation and then turns off. If you checked it only for a short period with the blower door off during self test mode, I'd put a jumper in, described in troubleshooting, and cycle the system. The jumper bypasses the thermostat and will allow the furnace to run for an extended period. I'd make sure you're in the high fire mode (I think you can jumper to high fire) and watch it with the door off to see if the code is set.

I did both - test mode with the blower door open and test mode with the blower door closed. No errors with the door open, and errors with the door closed.

I think the system is marginally designed and I might modify it. I just don't want to make it worse! I think shortening the return flex is a good idea, and performing a good cleaning on the intake vents, and trying to modify them to get a good path to the intake is key. I'm not sure if they made this so long and convoluted on purpose though? Seems ass-backwards to me - shouldn't you want a return path with as low restrictions as possible?

-Wayne

[cabmandone]

Originally Posted by Wayne 962

The code is indeed 44 right now. Nothing else either. I bought some stuff at the hardware store to clean out the vents. The trouble is, I found some stuff down there that looks like it might have asbestos in it, so I FedEx'ed it to the testing lab in Los Angeles and I'll have them check it (by Thursday morning). Then if that comes back all clear, I will crack open the return pipe and tape a filter to it and suck air from the basement area and see if that makes a difference. I'll also clean all of the dust out too while I'm there.

-Wayne

I'd be a bit surprised if it's asbestos. That stuff hasn't been used in years. I don't know how old the system is or the home, but it would be unusual for there to be asbestos with a system that "new" (meaning Carrier MVP Infinity and all the flex duct) Take a look at that troubleshooting guide I linked. It will tell you what to look for with a code 44. I think the codes and procedure for correcting each starts at page 13 IIRC.

[Wayne 962]

Originally Posted by black73

LOL! Dude got all the money in the world and comes here for free advice rather than pay a competent AC Tech.

Looks like way too much dirt in the duct. Check for air leaks under the house pulling the dirt into the duct. Never run without a filter and do not pull air from a crawlspace. You are breathing that shat! Oh, and get your coils cleaned.
Hope that helps.

I'm with you - I don't want to be messing with this stuff. But we have the following issues:

1) My wife doesn't want non-family in our house during a pandemic

2) This house is not in Los Angeles (located in a mountain town about 400 miles away), and the 'local talent' of HVAC people is not the same as it is in Los Angeles.

As for the dirt, this is the intake that leads to the FAU - the filter is inside the FAU, so basically if any of this stuff gets loose, it gets in the filter. The house was redone around 2001 or so - I suspect this is just normal 19+ years of dust accumulation. Here's a better picture - this is the same shot above, just taken about eight feet behind it:



-Wayne

[cabmandone]

Originally Posted by Wayne 962

I did both - test mode with the blower door open and test mode with the blower door closed. No errors with the door open, and errors with the door closed.

I think the system is marginally designed and I might modify it. I just don't want to make it worse! I think shortening the return flex is a good idea, and performing a good cleaning on the intake vents, and trying to modify them to get a good path to the intake is key. I'm not sure if they made this so long and convoluted on purpose though? Seems ass-backwards to me - shouldn't you want a return path with as low restrictions as possible?

-Wayne

The longer the flex run, the more static pressure the system will see due to the corrugations in the flex duct, so shortening the length of the return wouldn't be bad. What size is the furnace/Air conditioner. I'll PM you my number if you'd like to talk shop a bit. Mind you, I haven't done this stuff in years but it's not too hard to figure out.

[cabmandone]

LOL! I swear I have 4 of those blankets in your pic in my family room (one for the wife and each of the kids) . I'm thinking maybe I need to up the temp in my house!

[Wayne 962]

Originally Posted by cabmando

You mention you used test mode. I believe this makes the system go through the stages of operation and then turns off. If you checked it only for a short period with the blower door off during self test mode, I'd put a jumper in, described in troubleshooting, and cycle the system. The jumper bypasses the thermostat and will allow the furnace to run for an extended period. I'd make sure you're in the high fire mode (I think you can jumper to high fire) and watch it with the door off to see if the code is set.

It does appear to start up in high fire mode, and then run for about 7-8 min and then fault after that - at least that's what it did the other day.

I'm not sure this system has worked well from day one - I think it's just been faulting down to low heat mode due to the crappy return line. As I mentioned before, this problem showed up in 2008 and they "fixed" it (again, the talent thing) by using a different brand of filter (according to the notes on the lid here). That doesn't sound like a good fix to me...

-Wayne

[black73]

Originally Posted by Wayne 962

I'm with you - I don't want to be messing with this stuff. But we have the following issues:

1) My wife doesn't want non-family in our house during a pandemic

2) This house is not in Los Angeles (located in a mountain town about 400 miles away), and the 'local talent' of HVAC people is not the same as it is in Los Angeles.

As for the dirt, this is the intake that leads to the FAU - the filter is inside the FAU, so basically if any of this stuff gets loose, it gets in the filter. The house was redone around 2001 or so - I suspect this is just normal 19+ years of dust accumulation. Here's a better picture - this is the same shot above, just taken about eight feet behind it:



-Wayne

Totally understand. You might want add a filter at the wall in the pic.

[Wayne 962]

Originally Posted by nota

I run 4 filters two on the door to the a/c closet one washable to trap dirt dust and hair one super disposable #9 the highest filter for smoke pollen ect

and the same on the bottom of the a/c unit one washable one super #9

and the fan cage veins still gets caked with dust and needs cleaning !!
I suspect the fan is your problem limiting air flow and the motor over speed
but with the build up in the vents a system cleaning is needed or the improved flow
will quickly be moving stuff on the fan again

that would be my first step clean the fan vents and evap coils for better air flow

never suck under house air inside open the system to inside air if you must

I thought about running a filter on the intake door and looked into that last year, but then I read a bunch of stuff that said don't do that as it would add more restriction to the system. Dunno. Conflicting advice...

Question for the experts: Is there any downside or reason why I shouldn't take the return piping and make it as short and efficient as possible? There's no "design balance" between the supply and the return, right? I can take this long flex hose (24" or so wide) and reroute it to remove some of the bends and kinks, etc. Like this:



???

-Wayne

[cabmandone]

Originally Posted by Wayne 962

It does appear to start up in high fire mode, and then run for about 7-8 min and then fault after that - at least that's what it did the other day.

I'm not sure this system has worked well from day one - I think it's just been faulting down to low heat mode due to the crappy return line. As I mentioned before, this problem showed up in 2008 and they "fixed" it (again, the talent thing) by using a different brand of filter (according to the notes on the lid here). That doesn't sound like a good fix to me...

-Wayne

So was it setting the code with the blower door off?

[Wayne 962]

Originally Posted by black73

Yeah, I know. I'm just jealous because I don't have my own museum.

Guys, I'm really no different than any of you. I still like to do everything myself to know that it's been "done right". Having extra bucks to afford to have someone else come in and do it - well, that certainly doesn't guarantee that it's going to be "done right". What does Joe Walsh say? "Everybody's so different, I haven't changed". Funny, but my wife will attest to that. If there wasn't a pandemic around, she'd have me calling in the "experts". I'd still be doubting them...

Working on my first 914 25+ years ago, and working on the latest Probe 16 - it's all the same to me. The guy I bought the FIAT Testadoro from the other day - I was embarrassed because my garage at home looks exactly like my garage in Torrance from 25 years ago. No fancy floors, no ballbearing cabinets, no neon signs, etc. - it's all business. Granted, since then I've gotten a lot more and better selection of tools, but that's about it. The only real upgrade I made in the past ten years ago was a heater I installed last year (worth every penny!).



-Wayne

[black73]

Originally Posted by Wayne 962

I thought about running a filter on the intake door and looked into that last year, but then I read a bunch of stuff that said don't do that as it would add more restriction to the system. Dunno. Conflicting advice...

Question for the experts: Is there any downside or reason why I shouldn't take the return piping and make it as short and efficient as possible? There's no "design balance" between the supply and the return, right? I can take this long flex hose (24" or so wide) and reroute it to remove some of the bends and kinks, etc. Like this:



???

-Wayne

First, I'm no expert, but I do have some experience. Your idea looks good to me. I would get a new piece of flexduct if possible rather than reuse that old dirty one. You start moving it around, it will dislodge all that funk. Not good.

[cabmandone]

RE post #31:
Are the bends tight like a 90 degree elbow or do the sweep for the bend. The turns, regardless of sweep will increase static pressure. You mentioned it's a 24" flex. Looks like a central return system with only the one main return. If that 24" flex is crushed like in the pic, along with the extra turns and length, you likely don't have adequate airflow. If the supply duct is as crappy as the return, you could have bigger issues. Flex duct increases static pressure and the furnace might not be able to overcome the poor duct design.

If you look at your air conditioner size, you'll have a series of numbers and then see something like 024 (two ton) up to 060 (5 ton). The 24" should be sufficient for a 5 ton system but with the length and the kinks in the duct, even straightening it out might not help.

[Wayne 962]

Originally Posted by cabmando

I'd be a bit surprised if it's asbestos. That stuff hasn't been used in years. I don't know how old the system is or the home, but it would be unusual for there to be asbestos with a system that "new" (meaning Carrier MVP Infinity and all the flex duct) Take a look at that troubleshooting guide I linked. It will tell you what to look for with a code 44. I think the codes and procedure for correcting each starts at page 13 IIRC.

The material is some type of insulation between the dirt and cinder blocks around the ground near where the hoses are - it's not part of the system. The house was originally built in 1960 and then completely remodeled in 2001, but this piece of material looks pretty old and original (it's lining the foundation).

I have that troubleshooting guide printed out - it would seem to go through the motions of testing the system, and then says "look for a dirty filter and/or blockages". Which led me to look at the intake...

-Wayne

[Wayne 962]

Originally Posted by cabmando

The longer the flex run, the more static pressure the system will see due to the corrugations in the flex duct, so shortening the length of the return wouldn't be bad. What size is the furnace/Air conditioner. I'll PM you my number if you'd like to talk shop a bit. Mind you, I haven't done this stuff in years but it's not too hard to figure out.

I appreciate that - I'm going to have to wait until Thursday when the test results on the insulation barrier I found in the area come back.

thx

[Wayne 962]

I posted some videos!







-Wayne

[cabmandone]

The odd thing is, that return grille is a filter grille. It's designed to have a filter in it. From the looks of the pic, about a 2" thick 16x24 filter. If that 24" is oval shaped to fit that grille, it's part of the restriction as well. Then add all the kinks from going through floor joist spaces and you've reduced the effective size of the duct to a point that the static pressure can't be calculated.

[sammyg2]

Originally Posted by Wayne 962

Guys, I'm really no different than any of you. I still like to do everything myself to know that it's been "done right". Having extra bucks to afford to have someone else come in and do it - well, that certainly doesn't guarantee that it's going to be "done right". What does Joe Walsh say? "Everybody's so different, I haven't changed". Funny, but my wife will attest to that. If there wasn't a pandemic around, she'd have me calling in the "experts". I'd still be doubting them...

Working on my first 914 25+ years ago, and working on the latest Probe 16 - it's all the same to me. The guy I bought the FIAT Testadoro from the other day - I was embarrassed because my garage at home looks exactly like my garage in Torrance from 25 years ago. No fancy floors, no ballbearing cabinets, no neon signs, etc. - it's all business. Granted, since then I've gotten a lot more and better selection of tools, but that's about it. The only real upgrade I made in the past ten years ago was a heater I installed last year (worth every penny!).



-Wayne

you also reminded us what the American dream is all about and what makes this country great.
The land of opportunity, for those willing.