Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-11-2012, 09:38 AM   #1
Member
 
Join Date: Sep 2012
Posts: 54
Rewards Points: 75
Default

Furnace died. Need advice.


I posted before about my plans for a new heating system, insulting, etc. Well, my furnace just died and we've already had snow. For two days we've used blankets and a small space heater. I'm now totally settled on running a natural gas forced air furnace long-term (before I looked at water heat, no more). I may have a line on a cheap used furnace to make it through the winter as we will have to borrow to do even a new furnace, much less the other work that has to be done.

Here are my current pressing questions. If you want more details, read the next post, which is rather long.

What are the pros and cons of variable speed motors? I'm told they're far more expensive, but I'm seeing a Haier the same as a Goodman but with variable speed and it's only about $100 more.

Anything to avoid or any special deals I should know about? I'm in the middle of Michigan and we've already had snow, though nothing stuck. I need something around 80,000BTU output and was thinking probably ~95%.

Thanks. For more info, see the next post or just reply to this if you're not curious.

beengone is offline   Reply With Quote
Old 10-11-2012, 09:39 AM   #2
Member
 
Join Date: Sep 2012
Posts: 54
Rewards Points: 75
Default

Furnace died. Need advice.


Again, unless you want details,

First, my ducts are not adequate in any way, nor is my return. It's a 1900sqft house built in the 1870s with a octopus for ducts. There are lots of bends and only a single register upstairs though there are 6 rooms plus a landing. I cannot afford to redo the ducts now. So, whatever I get has to be able to hook up to my existing system and I'll have to cut an extra return, even if in my basement for now.

Second, I want to either go ultra-cheap (hence my looking for used) to make it through the winter and work on this Lord willing next year. Otherwise, I want to borrow from a fiend to purchase the furnace I want long-term and just hook it up for the winter then move it and do ducts when we can afford.

Currently there is no insulation, though I'm hoping to get the attic done by the end of next week; this little furnace project cut into that time. Good news is the house isn't drafty and has all but 6 windows replaced. I've done weatherstripping on doors and am almost finished with plastic on windows. It holds heat better than expected. Though it was 30 degrees last night, none of the house dropped below 54 except the end of the crawl space (we have partial crawl, partial basement).

So, questions. If I don't find a cheap used furnace, what am I looking for? I talked with an HVAC guy I trust who said variable stage is definitely worth it, but he doesn't go for variable speed. He said the variable motors add a lot of cost. I found a Haier 95% 90,000 btu variable speed, two-stage for $950, which isn't much more than the Goodman two-stage without variable speed. Could someone inform me of pros and cons to variable speed?

I'm hoping in the long-run to run multiple zones. There's a project I'm looking into that's an open-source programing project that looks promising and is very inexpensive, though I'll have to do a lot of the work. I only bring that up because if I do that I may end up with every room having it's only thermostat and zone. So, figure 3-10 zones. I'm not sure if that info affects the recommendation and need for variable speed. Keep in mind, it's all one zone now and I can't change that soon.

Anything else I should be looking for or at? Thanks in advance for all your help.

beengone is offline   Reply With Quote
Old 10-11-2012, 01:40 PM   #3
Member
 
biggles's Avatar
 
Join Date: Jan 2008
Location: Long Island
Posts: 3,630
Rewards Points: 2,000
Default

Furnace died. Need advice.


.do you want help to get the clunker going again and "keep it simple" on a new install 3 to 10 zones on the new one..the furnace vblows hot air it isn't brain surgery and the house if insulated windows to walls should hold the heat in.... are the exsisting supply ducts tight and the return is it 100% from the heated space not sucking in attic or basement cold temps....standing pilot induced draft how was it last winter.... forget the used one...unless the heat exchanger is cracked with the exsisting we'll get it going....lets hear back......
biggles is offline   Reply With Quote
Old 10-11-2012, 01:56 PM   #4
Member
 
Join Date: Sep 2012
Posts: 54
Rewards Points: 75
Default

Furnace died. Need advice.


Quote:
Originally Posted by biggles View Post
.do you want help to get the clunker going again and "keep it simple" on a new install 3 to 10 zones on the new one..the furnace vblows hot air it isn't brain surgery and the house if insulated windows to walls should hold the heat in.... are the exsisting supply ducts tight and the return is it 100% from the heated space not sucking in attic or basement cold temps....standing pilot induced draft how was it last winter.... forget the used one...unless the heat exchanger is cracked with the exsisting we'll get it going....lets hear back......
Sorry, can't believe I didn't mention how it failed. It is a broken heat exchanger. So: done. All ducts are in basement except the one that runs up to the upstairs. I'll mess with large trunks and breaking it out correctly when I can afford to do ducts.

About variable speed blowers?
beengone is offline   Reply With Quote
Old 10-29-2012, 09:40 AM   #5
Member
 
Join Date: Sep 2012
Posts: 54
Rewards Points: 75
Default

Furnace died. Need advice.


Here's the update. I found a local contractor who sold me a used Bard 80,000BTU 90+% for $200. I picked it up and learned a lot about HVAC. Of course, it came with no standing warranty, but he did warranty that it would work. He honored it when it wouldn't and it had a clogged exhaust fan or vacuum diaphragm. It seems to be working just fine now after cleaning out the condensate drain and a lot of cutting and splicing.

Friends and family helped me move it and install. I made the bonehead mistake of removing the old return air box and both plenums which I later had to just reinstall and hang. I also had to convert the old plenum due to it's sizing difference. The new furnace heat outlet was longer and narrower than the existing plenum. I'm told I need a larger plenum, but don't understand how plenum size really matters. Could someone give me the quick rundown on how and why to size it a certain way? I was also told I need to add at least two more 6" vents in the house to let more air out. I understand to a certain point that i could be restricting the blower, but if I run three trunks and damper one zone entirely, I'm right back to square 1, right? I do need to add more, so it's not a big deal, but trying to clear that up. And, I can't spend any money on this any time soon - I won't be stressing the motor in some way by waiting, will I? Hopefully I find someone ripping out a bunch of rectangular duct soon and can buy some cheap.

Other than that, I have to increase my return sizes a bit (double) and eventually I have to run heat to the upstairs rooms instead of just the landing, move most of my vents around as they're mostly in the middle of floors or on interior walls (no idea what clown installed this systems). I also have to get the condensate out of the house and posted about that here.

Thanks for all your help everyone. We're blessed to have heat now that it's getting cold and the space heaters we were using were struggling.
beengone is offline   Reply With Quote
Old 10-29-2012, 09:51 AM   #6
Member
 
Join Date: Sep 2012
Posts: 54
Rewards Points: 75
Default

Furnace died. Need advice.


Quote:
Originally Posted by biggles View Post
.do you want help to get the clunker going again and "keep it simple" on a new install 3 to 10 zones on the new one..the furnace vblows hot air it isn't brain surgery and the house if insulated windows to walls should hold the heat in.... are the exsisting supply ducts tight and the return is it 100% from the heated space not sucking in attic or basement cold temps....standing pilot induced draft how was it last winter.... forget the used one...unless the heat exchanger is cracked with the exsisting we'll get it going....lets hear back......
Just realized I didn't answer many of your questions all that time ago. I'll worry about good controls and zones at a later date; for now I have to do this as cheap as I can. I was looking seriously at a new furnace, but just couldn't afford it. The guy who sold me this pulled it out of a house where it was working perfectly, but the customer wanted newer, bigger, more efficient and was willing to pay. For $200, it's worth a shot.

Right now I'm drawing some air from the basement, which is staying around 54 at night so far. I'm cutting that down as I open up more return air in the living spaces. I've been taping off joints in the ducts as I reinstall and, again, hope to find trunk runs cheap and will tape them off well as I go. I have to pay attention to temperatures in the far end of the crawl space which is above ground and gets cold. Of course, that's where 90% of the plumbing is...

As for last year, we weren't here. We moved in late last spring and used the furnace for only a couple days. We just found out it had been condemned by the contractor who later sold me this other furnace. He shows up to help unclog the vacuum and says, "I've been here. I condemned this furnace last year for a client who put an offer on the house." Good news is it's a small town and I can call this fellow to see if he notified the seller of the furnace problem. If so, I'm going to get the money for my furnace inspection back. GRRR. (Not sure why no red 'condemned' tag was on it, but that's an altogether different story.)

beengone is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lennox Furnace G27M Series Unreliable operation: pressure switch or else? sheppard1977 HVAC 7 01-14-2013 05:42 PM
Quote for new furnace. Reasonable? dengle HVAC 16 03-04-2012 07:01 AM
New Furnace Install AustinPorsche HVAC 1 05-12-2011 10:16 PM
wood furnace advice paul1969f HVAC 18 10-24-2009 12:07 PM
Need New furnace advice. Unregistered HVAC 3 10-23-2006 09:13 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.