Heater Vent and Exhaust Not Connected

ZekenSpider · 11-03-2009, 10:35 AM

This last weekend we used the heater in our new (2010) TM 3326 on our first extended trip in cold weather. We had good heating performance but also had an obvious smell of combustion products inside the TM. The heater ran about every 30 minutes throughout the night and there was no CO alarm.

After investigation, I found the outside heater vent cap exhaust area was cold to the touch and I could not feel any hot exhaust discharge, even though the heater was running.

After removing the furnace compartment cover, I found the combustion air inlet and exhaust ducting had never been connected at the factory (the combustion vent cap and tubes are the wrong part number and length). The tubes were about 2" too short. The burner was pulling combustion air from inside the TM and putting all of the exhaust gases back into the TM.

I made temporary connections using aluminum foil to get us through the trip and have yet to get the correct parts for a permanent fix.

I recommend everyone verify proper operation of the heater exhaust be feeling that hot air is coming out of the top hole of the vent cap on the outside of the TM.

I am certain my dealer would fix this, but he is too far away. I'm waiting for a call back from TM about part availability.

Jerry

OneMoBear · 11-03-2009, 11:16 AM

Yikes! Are you sure your CO alarm is working? Glad you're ok!
Malinda

**wbmiller3** · 11-03-2009, 03:12 PM

That sounds dangerous! Our heater vent gets HOT, good place to warm your hands. I sort of resent all that hot air going out, but am glad the combustion products go too.

11-03-2009, 09:35 PM

My 2008SL has a smell when the heat is turned on too. And not a minor one. I will be checking the connections also. It's too bad the really important items aren't checked more closely. I will let you know after the weekend. Thanks Jerry! Robert

Oh and I can't forget to disconnect the heater element on the Carrier A/C unit too.

11-07-2009, 09:13 PM

I checked my connections and found them to be correct. I also took the home carbon monoxide alarm from inside the house to check the air coming from the heater,in the trailer, and it did not register anything. I was just curious to see how the alarm measured the exhaust so I took the house alarm and held it to the exhaust and it never read anything. I guess it's time for a new alarm.

So now does anyone know why there is some odor coming from the heater. It looks clean inside and has probably been used very little. Maybe with some age whatever gives off the odor will go away.

**Bill** · 11-08-2009, 08:51 AM

When a new furnace is turned on for first time, and for a couple hours after that, it smells bad. The furnace manufacturer puts some sort of waxy preservative on the metal parts so the unit won't rust while it is in storage and shipping, and it smells as it burns off. Let the furnace run for a couple hours - it will go away. There is nothing TM can do about this, short of hooking up every furnace and running it at the factory. If you have any suggestions, contact them.

A correctly operated unit generates virtually no carbon monoxide - that's why you didn't see any. It is built to operate with a surplus of air in the fuel mix, which ensures that all of the fuel is converted to CO2 and water. The CO scare stories that you hear arise from a unit that is operated with blocked or restricted air intake, or misadjusted in some way. That's not to say that you can or should operate it without venting - you shouldn't - but rather that your test results are exactly what is expected.

Bill

11-08-2009, 10:04 AM

I read somewhere that a better way to test a carbon monoxide detector is to use car exhaust.

I have never tried that.

11-08-2009, 11:42 AM

Thanks Bill and Wayne for the answers to both questions. I'm sure my heater has NOT been used for a couple of hours, so that explains the odor. I had no idea the exhaust had so little CO in it. I guess that's why Jerry's CO detector didn't go off too.

Now the next question because you two were so fast and accurate. Why does my wife want so many purses and shoes? And what can I do to change that?

11-08-2009, 12:01 PM

With all this heater talk has me wanting to try ours out but will have to wait here for Janurary. Robert, they were born that way.

11-08-2009, 06:50 PM

Put the Carbon Monoxide checker to the car exhaust and it took about 25 seconds to get a reading of 625 on the display and did not go into alarm. Then waited for the display to go back to zero and put the CO checker to the TM heater exhaust outside for 90 seconds and no measurement. Interesting. Robert