Heater Short Cycles - Vent in Steps the Apparent Culprit

[ksucats]

Was in New Mexico last week and although the days had record breaking heat, the nights were the typical cold (well not quite as cold as February normally is but that is another story - but I digress).

We noticed this in January when we were using the coach but thought it to be normal for the larger heater - much larger than in the coach we traded. However, this time I decided to see if that was the case - found that the vent located in the stairs was directing warm air directly onto the thermostats. The furnace would kick on, heat would start and the furnace would shut off the propane, unit would cool down properly and the fan would shut off. About 30 seconds to a minute later the process repeated. The bedroom never got warm, the coach itself stayed very frosty. So, I put a towel over the vent and now the furnace stayed on until we got heat through out the coach and everything warmed up. Took the towel off later to retest with the same results.

As it gets very warm in that area (heater ducts to the basement and forward area) I need to find something that is non-flammable but sturdy to put in there. Was thinking of a 'shuttered' vent so we could open or close it but there is really no need for that vent at all given that the bathroom has a vent less than a foot away from this one. Then within another two or so feet is one for the bed room. LM sure didn't waste any tubing running vents very far.

In any case, thought I'd bring this up in case anyone else is having a similar issue.

 

[Garypowell]

Certainly many have put in shuttered vents. I only have the problem with the bathroom vent and bought a magnetic cover. Once we found the sweet spot we don't touch it and it stays in place.

But out you also need to be sure your furnace can move enough air to keep running.

 

[danemayer]

Suburban strongly recommends not doing anything that reduces airflow from the floor registers. Reduced airflow can lead to higher temperatures in the combustion chamber which may cause the high-limit switch to open, shutting off gas flow.

That said, many people have put in adjustable registers, or have partially/completely blocked at least one register, without any apparent negative effects.

If you do restrict airflow, I'd suggest you make yourself a note so that if in the future you start having furnace problems, you remember to take another look at the registers.

 

[gasman]

So...if you don't need the heat provided by that duct, what about disconnecting it from the stair vent and letting it dump its air into the belly instead. You could put a dampered vent in the stairs so you could close off the hole. It could always be reconnected in the future if necessary.

 

[TxCowboy]

Ksucats, we noticed this same situation in our Key West -- stair vent blows the air directly on the thermostats.

We didn't use our furnace much this winter and instead relied primarily on the fireplace and a small space heater in the bathroom/bedroom. However, it's good to know that we have a work-around with the stair vent when it is time to rely on the furnace.

Thanks for posting your experiences!

 

[ksucats]

Wife said that there is a vent of some type on the front by the bed that has little to no air coming out - I'll have to check on it. If it is there I think blocking the one off will actually improve that. As for using it to head the underbelly that may help in extremely cold temperatures -- have had it in -10 so far with no problems but this could make it better.

I'm still leaning towards an adjustable vent for the immediate future to see what problems may result.

Jeff: we used our fireplace heater a bit during the football tailgates and also our heat-pump AC unit one time. Problem is that they don't contribute any heat to the under-belly so some lines could freeze. The propane heater is needed to keep things in that part of the coach above freezing.

As an aside, I forget where I saw it - I'm sure it was in one of the forum posts but I got the wife interested in the electric 'Cheap Heat' item. ( http://www.rvcomfortsystems.com/# ) An add-on that goes after the propane heater but uses electric heat replacing propane where you have shore power. Given that we went through a 40 lb bottle of propane last week, and electricity was provided by the campground, having such would have saved us some money, and kept the stuff in the basement and under belly warm(er) and happy. Now to figure out how many bottles of propane need to be saved to cover the cost of the 'Cheap Heat' and installation :angel: (that's money just flying away LOL ).