# lennox conservator g11e problem



## GetYourShineBox (Sep 20, 2009)

is your ignition control board a johnson controls model? i looked around and found similar problems with lennox and one of the remedies was that the board was bad and needed replacing.


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## beenthere (Oct 11, 2008)

A G11?

Thats 30 some years old. HX needs checked for cracks.


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## AWILLIAMS64 (Oct 6, 2009)

i dont see a board of any kind. The only thing i see is a covered box marked honeywell with 3 big wires going in and 2 coming out and then a pilot contol box and it doesnt have a name on it just a model #g60qhl1. I know its old, i had it checked a few years ago but i am hoping to get 1 more year out of it. I had to replace my windows this year,,,still waiting on that to be done and next year is hopefully going to be a new heating and cooling system. Is there a way i can check the hx myself?


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## SKIP4661 (Dec 3, 2008)

I think this furnace uses the johnson module that mounts to the gas valve. They can be swapped for a universal module but takes some engineering to make it work. I would do as suggested and have the heat exchanger inspected.


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## AWILLIAMS64 (Oct 6, 2009)

it is mounted to the gas valve


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## AWILLIAMS64 (Oct 6, 2009)

i have a tech coming out this morning to take a look at it. Hopefully i can get through another winter with it. IF i have to get a new furnace i will want to replace the ac along with it. It seems everyone is going with a heat pump and furnace system. Are these better than an ac unit and a heater?


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## AWILLIAMS64 (Oct 6, 2009)

beenthere said:


> A G11?
> 
> Thats 30 some years old. HX needs checked for cracks.


do you think its really that old? even with an electronic ignition system? I am not doubting you just another question..


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## beenthere (Oct 11, 2008)

AWILLIAMS64 said:


> do you think its really that old? even with an electronic ignition system? I am not doubting you just another question..


Yes. Electronic ignition has been around a long long time.

I could be off by a few years. And may be its only 28 years old.


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## AWILLIAMS64 (Oct 6, 2009)

i had the tech come out this morning and guess what, heat exchanger has a large crack in each bank. I am now waiting to get an estimate on a new furnace and heat pump. He didnt even charge me for the service call and got it working for now.


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## TJ_in_IL (Aug 24, 2009)

Ah.... the Revenge of the Dura-Curve strikes again!


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## AWILLIAMS64 (Oct 6, 2009)

TJ_in_IL said:


> Ah.... the Revenge of the Dura-Curve strikes again!


 not quite sure what that means. I got a quote for an american standard 100k 90+ gas furnace with a 3t heat pump for $4500 installed. or just the furnace for $2000 installed. My central air was put in in 1991 so i am leaning toward a whole new system.


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## TJ_in_IL (Aug 24, 2009)

What I meant was there have been numerous issues with the Lennox Dura-Curve design, resulting in HX cracks. I just recently changed mine, because of this same issue. That is also why many have posted to you to have it checked for cracks.


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## beenthere (Oct 11, 2008)

Ask them to do a load calc. And see if that is the size you really need. 
They may be sizing by sq ft. Which just cost you more money.

You can do your own, if you want. HVAC Calc

It has a 49 dollar fee.
But is well worth it.


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## hvac122 (Dec 10, 2007)

Now to the next step. How did they come to the conclusion as to what size system you need? Did they perform a manual J load calc? If they just guessed from sq footage or old equipment size then you will not be sized properly.


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## AWILLIAMS64 (Oct 6, 2009)

hvac122 said:


> Now to the next step. How did they come to the conclusion as to what size system you need? Did they perform a manual J load calc? If they just guessed from sq footage or old equipment size then you will not be sized properly.


i think they just went off sq ft of my house which is about 2100sq ft including basement. The first company is a small family operated business that i have known the family for about 30 years. They are really small and only have family working there but have been in business for a long time. Tomorrow i have another company coming out, and see what they have to offer.


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## beenthere (Oct 11, 2008)

100,000 90% furnace for only 2100 including basement. Thats a bit over sized. Unless your winter temps are in the -30°F range.

Or you have no insulation, and mostly windows for walls.


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## SKIP4661 (Dec 3, 2008)

Around here those Duracurve heat exchangers have a nickname, Duracrack.

Have a heat load calc done. A system that is properly will provide the most comfort.


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## AWILLIAMS64 (Oct 6, 2009)

so is a heat pump and gas furnace better than a gas furnace and regular central air? Will the heat pump be better in the summer for cooling and then as i understand, the heat pump will also produce heat down to a certain temperature so the gas furnace does not have to run? the tech also said that he could add a humidifier to the system for an additional $225..are these really worth it?


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## beenthere (Oct 11, 2008)

Dual fuel/hybird(heat pump with gas or oil furnace) systems do save you on your heating cost.

As far as cooling. A heat pump or straight A/C, cool about the same.

How dry was your house last winter. That will determine if a humidifier is worth having or not.


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## AWILLIAMS64 (Oct 6, 2009)

pretty dry, i also have a wood burning stove in the addition on my house which makes it especially dry in that area.


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## AWILLIAMS64 (Oct 6, 2009)

i had the 2nd company come out today, he took measurments and notes and is going back to his shop to do a load calc. He also recommended the heat pump/gas furnace. He also stated that i only needed an 80% furnace because of the time it is actually used but i thought 90% would be better. Am i wrong in this aspect? He is supposed to have me an estimate by the end of the day so just waiting now...


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## beenthere (Oct 11, 2008)

A 90% will help your resell value much more then an 80%.
So even if you don't use the furnace much. It is still better to go with a 90%+, then an 80%.

You never know if a buyer 10 years from now will use the wood stove.


Most of your dryness comes from using the wood stove. If its combustion air is taken from the house.
It takes a good humidifier to overcome the amount of fresh air a wood stove needs for combustion.

In your application. If the wood stove combustion air comes from the house. A steam humidifier would work better.
An EWC S2020 would be a good choice. Its expensive, but can add 22 gallons of water to the air a day.


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## AWILLIAMS64 (Oct 6, 2009)

since i am going to replace my furnace with something, are these johnson modules worth anything since they are so common to go bad and hard to find? that part of the furnace works great!


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## AWILLIAMS64 (Oct 6, 2009)

In your application. If the wood stove combustion air comes from the house. A steam humidifier would work better.
An EWC S2020 would be a good choice. Its expensive, but can add 22 gallons of water to the air a day.[/quote]
yes, those are expensive!

so would it be worth it at all to get the add on humidifier for the furnace? i think he said he uses aprilaire humidifiers, around $225 installed


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## beenthere (Oct 11, 2008)

That Johnson control isn't really hard to get.

You would probably need an Aprilaire 700 connected to the hot water line. If you want to get near enough moisture in the air.

But I doubt it would be enough while your burning wood, to get close to the humidity you would want. But would be better then not having a humidifier.


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## AWILLIAMS64 (Oct 6, 2009)

i am supposed to get my new furnace and heat pump installed on wednesday. I am getting and american standard 90+ gas furnace and 13 seer heat pump. I would like to go better seer heat pump but unfortunately my budget will not allow for it. i got several quotes, 2 from 1 campany. 
here is the quotes i got from one company using american standard contemporary furnace and allegiance ac unit. they also did a load test.

13 seer ac unit 30000(not heat pump) 92% 80000btu furnace(gas) and honeywell thermo. $7148 installed 
(claims 12% gas reduction and 38% air conditioning savings.

15 seer heat pump, 30000 80% 100000 btu variable speed 2 stage furnace digital thermo. $8940 installed
claims 52% electricity reduction and 60% gas reduction. 

I also got a quote for 100000 btu 90+ and 13 seer heat pump using rheem equipment for around $6500 installed

I have a friend in the business that also uses american standard equipment that i was able to get ahold of. He is a very small family owned business that gave me a great deal so i am having him do it. Using the same furnace from quote 1 100000btu 90+ furnace and a 13 seer heritage heat pump along with touchscreen thermo for $4500 installed. He said he can also add in the aprilaire 600a humidifier for around $250. i am going to ask about the difference in price of the 700. 

I am not going just for the cheapest price, its just what i can afford to do at this time...(medical bills really suck)..I just hope i am making a smart choice for my family and home. I really appreciate the help all of you have given me. Its great to be able to get opinions from people not trying to get my money.


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## beenthere (Oct 11, 2008)

Was your old furnace 100,000 BTU.


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## AWILLIAMS64 (Oct 6, 2009)

yes it is


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## beenthere (Oct 11, 2008)

Get more estimates.
Do your own load calc HVAC Calc.

Newer furnaces require far more air flow then older ones did.
Your duct system is probably under sized. And a 100,000BTU 90% will probably end up tripping on its high limit. Or, you'll end up with lots of noise from your duct system.

You may only need a 60,000BTU 90%. So a load calc can save you money up front with a smaller furnace that cost less. And saving on gas consumption.


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## AWILLIAMS64 (Oct 6, 2009)

upon further inspection i found my old furnace to read input 110,000 and bonnet cap 88000 btu.


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## beenthere (Oct 11, 2008)

You should still spend the money and see what size you really need.

While a 100,000BTU 90% would only be 2,000 BTUs more output.

It still will need to move more air then your old furnace. And could make your system loud. And cause higher heating bills then you currently have.

Common old gas furnaces had temp rises of 80°.
But, going conservatively, and saying your old furnace had a temp rise of 70°, it would have moved 1164CFM.
A new 100,000 BTU 90%er at a temp rise of 55°(common) will need to move 1515 CFM. A 30% increase.


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## AWILLIAMS64 (Oct 6, 2009)

unfortunately due to the inclimate weather we are having i was forced to get a furnace installed that i thought would best suite my my needs and what i could afford. I went with the 100k btu 90+ furnace, heat pump and humidifer. It seems to be working good. There is a couple of small things that the installer has to come back out tomorrow to finish up. For some reason my outside temperature on my thermostat is not working.,.i got a white rodgers thermostat and the outdoor sensor is a honeywell so he thinks that is the problem. And also i had the humidifier hooked up so it will run even if i only have the fan turned on to circulate air and i when i came downstairs earlier, the water was running through but the blower was not on.. I think the humidstat maybe was set too high. I turned it down and it kicked right off. 

the one company did a heat calc test. measured my house, my windows, vents, return vents, etc. they are the ones that had the 2 quotes. I went ahead and went with what the company i chose. I hope it will save me some money over the long run. 

I really appreciate all of the help you have given me, althoug i may not have done all you suggested, you really helped me understand alot of things about hvac. I will let you know how it works out in the next few weeks. again, thanks for all of your input.


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## beenthere (Oct 11, 2008)

Since you went dual fuel. You probably won't notice problems until it gets cold enough that the furnace has to take over.


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