Please recommend a new furnace

Users who are viewing this thread

Murphy625

Member
Messages
161
Reaction score
0
Points
16
Location
Michigan
My friend just had his furnace die. Its a Bryant 350mav model and the heat exchanger corroded.

That furnace has been a pain in the butt every single year he's owned it. 4 out of 5 years it would burn out the hot surface ignitor, once we had to replace the main control board, then his fan started going bad, and now we discovered the heat exchanger is bad. What a piece of junk! This was supposed to be a high effeciency 90+ unit he purchased in 1998 and its been nothing but problems. What's funny is that its spotless clean and looks like it was installed yesterday. Even the heat exchanger looks clean.

So he wants to purchase a new furnace but he doesn't want to get one that has been engineered to put money in the pockets of repair people. (he does all his own repair work anyhow but it still a pain in the rear when it malfunctions in the middle of single digit temperatures outside)

Any recommendations?
Thanks,
 

Stuff

Well-Known Member
Messages
1,221
Reaction score
130
Points
63
Location
Pennsylvania
A Consumer Reports article stated that furnaces typically last between 15 and 18 years.

Also said that the installation was more important than the brand. You need a good HVAC tech. One who will spend the time figuring out what he needs as well as if his ducts have issues that need fixed.
 

Murphy625

Member
Messages
161
Reaction score
0
Points
16
Location
Michigan
A Consumer Reports article stated that furnaces typically last between 15 and 18 years.

Also said that the installation was more important than the brand. You need a good HVAC tech. One who will spend the time figuring out what he needs as well as if his ducts have issues that need fixed.

15 to 18 years is an interesting figure. My condo (rental) furnace was installed in 85 (original), and still going. 15 years seems insufficient for a $2000+ investment.

Can you elaborate on how the installation is more important? What would duct work have to do with furnace wear and tear?
 

Dana

In the trades
Messages
7,889
Reaction score
509
Points
113
Location
01609
Most furnaces installed in the US are more than 2x oversized for the actual heat loads (often 3-4x oversized.) While that doesn't affect efficiency, it reduces comfort and equipment longevity. If it's oversized for the ducts it's even worse. Replacement time is an opportunity moment for getting it right, and it usually means down-sizing, sometimes by a LOT!

If you have a fuel-use history that we can compare against heating degree-days for that location (downloadable from degreesdays.net) for some winter billing periods we would determine what the minimum output would be to cover the heating load with the existing ducts as-is. (If they're leaky ducts or an unbalanced duct system design it would overstate the actual heat load). Then, with that information you could at least come up with some units of an appropriate size.

If the original furnace is 5x oversized for the load and appropriately sized for the ducts, there could be issues of the ducts being too oversized for a smaller unit, but those situations are pretty rare. Oversizing by 1.5x is not a problem and still has reasonable recovery rates from overnight setbacks. At 2x oversizing you're at the threshold of diminishing comfort, at 3x you're wading into equipment life issues.

This bit o' bloggery might be worth reviewing before buying a new furnace.

Most people are nervous about down-sizing by half, nervous that it might not keep up during a cold snap. If your 99% outside design temp is 0F and you're at 1.5x oversizing, it means it can keep up even at -35F. Do you really need it to keep up at -70F, or -150F? Sizing it by a fuel-use analysis is in some ways preferable to a Manual-J heat loss calculation for a replacement unit, because the system inefficiencies of duct leakage and air-handler driven infiltration are already built in, and you don't have to take a WAG on the average infiltration rates either.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks