Furnace expertise?

[AJP]

Just discovered my 11 year old KeepRite DC90 furnace has a very noisy (squealing) "combustion draft blower" ... as it is starting up for the new cold season. I had noticed water on the shelf (also leaking to floor) under the blower last year but ignored it. I thought the drain from the furnace had plugged but their was no apparent obstruction. Now I see water again and what sounds like a bearing shot in the blower where the water seems to originate.

An online search for this problem and model finds several different sources pointing to a faulty heat exchanger and warns of CO danger. Something about "popped ring" . Not sure how these symptoms correlate though.

Anyway I sent a note to KeepRite head office and get a fairly standard response regarding warranty and the need to contact a qualified service facility (no argument there!) BUT also this comment:

"Further, this unit is designed under a negative pressure therefore making it impossible for CO to enter the air stream of your home"

Is this true?? Is this BS? What does it mean "designed under a negative pressure..."??

Should I swap this out for a Trane?? I am now worried that the negative pressure they are talking about might be the vacuum between the ears of the guys who support this product ....BUT admittedly I am NOT an expert ... just looking for some guidance.
Thanks!!

PS - when I put a level on the furnace it does slope away from the drain side of the unit fwiw

 

[John Galt]

I'm not familiar with this specific furnace, however in most cases the "combustion draft blower" is located downstream of the heat exchanger and when correctly operating it creates a negative pressure that prevents any combustion gasses from entering the heated airstream even if the heat exchanger has leaks. Given the high temperatures and moisture this blower has to endure, an 11 year replacement cycle isn't unusual with this design. Replace the blower motor and you should be good to go.

JG, aka Harry Tuttle
Harry Tuttle@Everything2.com

 

[AJP]

Thanks JG ... much appreciated ... I have the Service folks that installed the unit coming tomorrow ... I'll post up their findings when they have a chance look at it.

best.
AJP

 

[cruiser88]

Just discovered my 11 year old KeepRite DC90 furnace has a very noisy (squealing) "combustion draft blower" ... as it is starting up for the new cold season. I had noticed water on the shelf (also leaking to floor) under the blower last year but ignored it. I thought the drain from the furnace had plugged but their was no apparent obstruction. Now I see water again and what sounds like a bearing shot in the blower where the water seems to originate.

An online search for this problem and model finds several different sources pointing to a faulty heat exchanger and warns of CO danger. Something about "popped ring" . Not sure how these symptoms correlate though.

Anyway I sent a note to KeepRite head office and get a fairly standard response regarding warranty and the need to contact a qualified service facility (no argument there!) BUT also this comment:

"Further, this unit is designed under a negative pressure therefore making it impossible for CO to enter the air stream of your home"

Is this true?? Is this BS? What does it mean "designed under a negative pressure..."??

Should I swap this out for a Trane?? I am now worried that the negative pressure they are talking about might be the vacuum between the ears of the guys who support this product ....BUT admittedly I am NOT an expert ... just looking for some guidance.
Thanks!!

PS - when I put a level on the furnace it does slope away from the drain side of the unit fwiw

He is right...shut it down


KeepRite DC90 Heat Exchange ring popped Read the whole thing

I honestly I would fix it. If you have those gases coming into the home from the heat exchanger you are screwed until its fixed.

I am still a little puzzled on the water. Or I am just not seeing everything

 

[AJP]

Well it looks like it is going to be replaced with a Trane XV95. And they aren't exactly giving away the Trane furnaces these days despite the economy woes.

FWIW the Keeprite A/C has been motoring along for years - in fact that was why I happily went with the current Keeprite furnace unit. I suppose overall I cannot complain - more than 11 years and generally maintenance free for the most part. I hope I don't regret the decision to go to the Trane unit although all reports say it is one of the better units...

 

[cruiser88]

Well it looks like it is going to be replaced with a Trane XV95. And they aren't exactly giving away the Trane furnaces these days despite the economy woes.

FWIW the Keeprite A/C has been motoring along for years - in fact that was why I happily went with the current Keeprite furnace unit. I suppose overall I cannot complain - more than 11 years and generally maintenance free for the most part. I hope I don't regret the decision to go to the Trane unit although all reports say it is one of the better units...

Was the combustion chamber done in the old unit?

 

[John Galt]

The existing unit couldn't be fixed?
Why replace with Trane?
From my experience I'd recommend Rheem
http://www.rheemac.com
over Trane any day.

 

[AJP]

Thanks for all comments - appreciated very much! .. well the "current" plan is to sign the contract this week and install on Friday.

To answer some questions - I would certainly look at a Rheem or Ruud (my water heater is a Ruud and is 17 years old ... been pretty faithful - but now due for a replacement)

Frankly haven't looked at Rheem furnace and probably should but I can't seem to find Rheem furnaces locally (Toronto Canada) as readily as the Trane. As far as the current unit - the combustion draft blower is noisy and will eventually need replacing. Although since I first started to notice the fan squeal a couple of weeks ago when the furnace started running for the winter - the noise is diminishing. The Unit still leaks water on the apron and the intake plastic grate is heat cracked and shows scorch marks AND I have had several local sources confirm (including the Direct Energy guy) that they are aware of this model of Keeprite showing these symptons when the secondary heat exchanger is shot.

I am told that short of tearing down the furnace to confirm a faulty heat exchanger they will need to bring on site some expensive test equipment to probe/test for CO . Each visit is a day off work for me and a $100 service call.

If the heat exchanger needs replacing I am quoted about $700-$800 labour (parts are free under warranty). A new heat exchanger will be of the same design (and deficiency as the existing one) ALSO the fan is going to cost about $500 parts plus $400 labour to install (plus tax) ...so about $1700. Which gets me a 11 year old working unit.


The Trane runs $5600 installed (plus tax) including an external air intake (the Keeprite is drawing air from inside the house) and I qualify for a $1000 energy rebate from the government because of the DC fan motor. I think it may also be a "little" more effecient but honestly the Keeprite has been pretty efficient/cheap on Natural Gas so far .. although partly attributable to the fact that we keep the place at 65 F pretty much all winter (brrrr!!!- bring a sweater)

So those are the numbers - Would prefer to keep my money but it looks like if I go with a new unit I "save" the $900 + on the fan expense and recoup 1000 for the rebate ... 1900. The unit then costs me 3700 assuming the heat exchanger is good or $3000 if it isn't. If I get another 11 years on the new Trane ... it will cost me $28/month. If the unit does save the electricity they claim (with the newer DC motor) and the 95% efficiency is a little better than the 90% efficiency it may cost me a little less.

Seems to me one significant consideration would be ease of repair - is there a furnace brand that doesn't run a 7 hour labour job to R&R a heat exchanger??? Having a "lifetime warranty" on a heat exchanger is irrelevent if the labour runs a grand everytime you need to replace one. And it looks like the HE units are more prone to this sort of issue ....
thanks!!

 

[cruiser88]

I thought one of the heat exchangers was shot... That is why I said don't run it.


Good luck in what you purchase. Oh yea install some carbon monoxide detectors if you have not already.

 

[turbocruiser]

Just as another option, the Trane XV90i has the Trane/Honeywell "Clean Air Effects" built into it and saves some money. It is 90% efficient by brand (hence the 90 in XV90i) but it is actually 93% efficient. You'll save some money with the "lower" efficiency and also save some by having the filter thing in the furnace already.

 

[John Galt]

With that much potentially wrong with an 11 year old furnace I'd be looking at replacing rather than repairing too. Rheem 90+ condensing gas furnaces I installed that long ago are still running like new. I've never had problems getting good service from Rheem Canada ltd. 128 barton street west (l8r 2h2) p. o. box 2846, station a hamilton, ontario canada l8n 3p3 (416) 527-9194 I'm further west in Canada than you.

I'm biased because I've seen lots of problems with Trane equipment and nothing but hassle when trying to get warranty service or parts. If you've got a local Trane dealer you think you can trust now and in the future, then I can certainly see your point.

 

[AJP]

Thanks for the Rheem recommendation - I will try to reach them if I can b4 signing anything with Trane ... also thanks for the heads up on the clean air effects system in the xv90i - I think I have the same thing already in my current attached electrostatic air filter which was recently serviced ....and I was told I can continue to use it fwiw.


... and yep ...good advice! I just bought a second CO monitor for the kids rooms ... although there appears to be varying opinions on how well they actually work.