Really, Really, Really Hot

[swebster]

Has anyone figured out how to turn "off" the heater (engine) in their MH? I've replaced all of the heater hoses, free'd up the heater core control valve and no matter what I do with the dash control I have a lot of VERY HOT air coming from under the dash (mostly on the drivers side).

It not bad during the colder days here in the Midwest but when I'm traveling in the South I'm roasting! This was most recently an issue whe I was in Atlanta on an 80 degree day. Thought I was going to actually cook my left foot.

I read a service bulletin in the P30 manual that mentions two types of heater air boxes. One relies on the coolant control valve only to regulate the temp of the heater core and the other adds a flapper to control the source of air in the ducts (one way for heated air, the other for fresh air). I mentioned that the latter was far superior and that your could install an H shaped coolant valve in the other that would bypass coolant to the heater core altogether. I know I don't have the bypass coolant valve so I pulled the font panel (kick panel in front of the pass seat) but can't seem to figure out if I have the "better" heater box.

I'm hoping something is just stuck somewhere as I have to believe that no one would have accepted this amount of heat when the coach was new!

Looking for advice and experience. Looks like getting to the box is a big job so I'd like to have a small clue before I dive in.

[PeterH-350LE]

You could just install a simple on/off valve inline to keep the hot coolant out of the heater core.
Downside: running 10 degrees hotter in the already hot summer.

[74Argosy24MH]

Also check for air leaks around the engine cover. Seems like the heater would affect both sides.

John

[thenewkid64]

I ended up adding a seal to the edge of the dog house and it made a big difference. I laso have a 2.5 inch hole that comes up thru the top of the doghouse and the grommet was gone. A good amount of heat came in there.

I have bypassed my heater core like peter did, due to it leaking. I will replace it some day but for now it will stay bypassed.

I also reinsulated the whole doghouse with the stuff from camping world. It really cut down on the engine noises and seems to help with the heat too. I applied 2 layers on the sides and one on the top. I can now carry on a conversation at normal voice with my co-pilot.

[87MH]

The Xilver Xepelin has two 3" air ducts coming from the plenum, routed over the engine, and then through the air dam on top of the radiator on their way to the cabin air distribution system.

Both of the air ducts were chaffed when I purchased her, and one of the ducts had a significant tear in the fabric between the wire windings.

I did some bandaging on the hose with Aluminum Duct Tape, the all purpose fixer upper.

Don't know nothin' 'bout no better heater boxes, tho'.

[PeterH-350LE]

Originally posted by thenewkid64
..... I also have a 2.5 inch hole that comes up thru the top of the doghouse and the grommet was gone. A good amount of heat came in there.
.......

Yeah, I have that one, too. Handy for running some wires, but sure makes for a great aux heater, especially in summer driving with the heat having nowhere to go but up through that opening.
And, its located really close to the A/C air intake..brilliant!!

[74Argosy24MH]

I also have a 2.5 inch hole

Hey, I had that hole too. Finally something on mine that seems to be standard. The hole went through the plywood cover and had a base for one of those single column temporary tables. Welded a plate over the hole, seemed like a leaker to me.

John

[PeterH-350LE]

Originally posted by 74Argosy24MH


Hey, I had that hole too. Finally something on mine that seems to be standard. ...

Sorry, John, nice try.
The 2 1/2 hole on our models is right in front of the GM fuse block on a metal housing that is actually in front of the dog house.
Not something you would find unless you remove the entertainment center.

[74Argosy24MH]

I knew it was too good to be true. And an entertainment center? Must have been what the table top was called in the Argosy, somewhere to deal the cards.

John