# Cold Weather Problems - Help!!!



## johral (Jan 11, 2011)

Not sure what brand insert I have - it was here when we bought the house.

Unit works fine until the temp gets well below freezing...then it does strange things.

Wake up in the morning, and the pilot will be out - try to light it and maybe it will, maybe it won't.  If I get it lit, I will let it warm up for at least 5-10 minutes before turning the dial to ON.  Usually it will just go right out.  If it does stay on, when you turn the unit on via the light switch, the flame will start around the burner just fine, but then it backs up towards the pilot and will get really tall and only about 4" down the burner.  The flame will be almost 100% blue.

When that happens, I immediately turn the unit off (at the light switch), and the pilot will flicker like there is a high wind coming down the chimney, but it is dead still outside.

I thought maybe it might be due to the meter and 30' of the supply (in the garage attic) being exposed to the extreme cold, but the furnace and hot water heater suffer no ill affects.

Any thoughts?  I can't get a service guy out during our cold spell, and once it gets above freezing in the next day or two the issue will be gone again.

Thanks


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## DAKSY (Jan 11, 2011)

johral said:
			
		

> Not sure what brand insert I have - it was here when we bought the house.
> 
> *Help US here....Somewhere on the unit there is a manufacturer's name & a model number.
> Get that info & repost.*
> ...


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## johral (Jan 11, 2011)

Superior DT-500CMN - Warnock Hersey


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## DAKSY (Jan 11, 2011)

What I could find on your unit leads me to believe it's DV. 
If it's vertically vented, it could be an exhaust restrictor issue...
Even on a calm day the velocity at which the combustion air 
enters the box can take the pilot out. By restricting the exhaust,
that incoming air can be restricted as well.
You mention that it occurs on cold days...are you burning LPG?


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## johral (Jan 12, 2011)

I am hooked up to Natural Gas via the Utility Company's Meter - that's all I know about that.

There is a restrictor in the vent pipe - and yes it is vertical.  What is DV BTW?

It only happens on very cold days - as is the case today - can't even get it to light.


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## jtp10181 (Jan 12, 2011)

Does cold air leak out of the fireplace into the house? Maybe the glass is not fully secured.


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## johral (Jan 12, 2011)

I have removed and replaced the glass before, and it seems to be on correctly.  I do however feel lots of cold air coming out from underneath the unit, through the knockouts for electrical, gas line, etc.  The backside of the unit faces the garage, and it is all finished in firewall, so I can't access that area without cutting some holes.


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## jtp10181 (Jan 12, 2011)

The wall connecting to the garage behind the fireplace is probably not properly insulated and sealed up, but that is not really relevant to this problem.


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## DAKSY (Jan 13, 2011)

Do you have a multimeter? 
If not, borrow one or get an inexpensive one. 
Radio Shack has them for about $20...
Take a reading on the thermopile when the 
pilot is lit & the burner is off, by connecting to the 
TP & the TH-TP  (or TP-TH) on the valve terminal block.
You SHOULD be at 550Mv +/-...


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## johral (Jan 13, 2011)

I do have a multi meter - I will check it out.

Thanks


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## Wood Heat Stoves (Jan 13, 2011)

what valve system does this use, i have troubleshooting data avail in pdf..
pm me


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## Garjan111 (Mar 15, 2011)

Hi

First time poster here. I've had this same problem and I'm pretty sure I can help you. I assume this is vented up with a cap since it's a DT model.  If you have an older style cap the openings are too close together at the vent. They freeze up with ice and won't let the exhaust out causing the pilot and flame to go out only when it's real cold. Seems impossible but true as I've had to change about 5 or 6 of them. Just get a new style cap or cut ever other piece out and your ready to go.

Gary


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## johral (Mar 19, 2011)

Garjan111 said:
			
		

> Hi
> 
> First time poster here. I've had this same problem and I'm pretty sure I can help you. I assume this is vented up with a cap since it's a DT model.  If you have an older style cap the openings are too close together at the vent. They freeze up with ice and won't let the exhaust out causing the pilot and flame to go out only when it's real cold. Seems impossible but true as I've had to change about 5 or 6 of them. Just get a new style cap or cut ever other piece out and your ready to go.
> 
> Gary



Thanks - I will have a look at it (The light has gone out once more, but luckily  I was able to light it successfully).  The really cold weather is over for us til next year, but I will get it taken care of as soon as I can get up on the roof.

Is there a particular type I should replace it with?


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## Garjan111 (Mar 19, 2011)

The Lennox part # is  H2152

Like I said you can cut every other one also.

Gary


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