Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: oldguy on December 09, 2023, 02:27:07 pm

Title: Dash heat
Post by: oldguy on December 09, 2023, 02:27:07 pm
Since I've had the coach I takes a long time for heat to come out of the heater vents after it is turned
on. Like a few minutes and the same thing after changing from defrost to the heater vents with heat
coming out of the defroster. Is this normal.
Title: Re: Dash heat
Post by: Phranko on December 09, 2023, 05:12:32 pm
Takes ours a good 10-15 min before the air is really warm, that's with the engine at normal operating temp.
Is that normal..... IDK
Title: Re: Dash heat
Post by: oldguy on December 09, 2023, 06:07:36 pm
I wonder why it takes so long. I've never checked how long it takes but it is way to long.
Title: Re: Dash heat
Post by: Barry & Cindy on December 09, 2023, 08:26:56 pm
Not sure exactly what you mean, but if you have air flow from defrost when expected from dash or floor vents, the air deflector doors may not be responding to change. Defrost is always the default when things fail.

Is heat source from a running Cummins engine or AquaHot? Each operates very differently.
Title: Re: Dash heat
Post by: Tommy D on December 09, 2023, 09:48:03 pm
Takes ours a good 10-15 min before the air is really warm, that's with the engine at normal operating temp.

Same.

Mine takes a while to heat up and it will actually randomly start blowing cold air again then heat.???
Title: Re: Dash heat
Post by: oldguy on December 09, 2023, 11:09:29 pm
The defectors work fine but the air is cold. Maybe the hot air coming from the defroster is because
of the Aqua-hot, I never thought of that.
Title: Re: Dash heat
Post by: Phranko on December 09, 2023, 11:30:56 pm
Same.

Mine takes a while to heat up and it will actually randomly start blowing cold air again then heat.???
I've seen that too, but then it starts blowing warm/hot and stays that way.
We don't "run" the Aqua Hot while driving.... read somewhere the engine is heating everything at that point.
Title: Re: Dash heat
Post by: Journey, Roam, Explore on December 10, 2023, 12:09:15 pm
Peter does your dash temperature switch work? Mine doesn't and I can't find a replacement for it. I've tried. Even the company that supposedly made it doesn't know what it is when I called them.  This is a rheostat switch that has seven wires going to it The other thing is I'm thinking is it could be your vacuum pump being slow to switch it over. I switched mine out with a new one two years ago but it didn't make any difference. Now I either have cold air blowing through the vents or I switched to the defrost and then I get hot air. But only from the vent next to the windshield not near my toes where I really want it...
Title: Re: Dash heat
Post by: oldguy on December 10, 2023, 01:16:37 pm
I don't suppose there are any drawings on how the dash heater controls work as that it takes
so long for heat to come out when the floor and dash vents are turned on. I leave my heat
valve on hot all winter so when the engine is hot why does it take so long for heat to come out.
It make no sense to me. I'm going out to see it I can make any sense to it.
Title: Re: Dash heat
Post by: turbojack on December 10, 2023, 01:24:19 pm
This depends on year of coach. Newer coaches have a micro computer run the AC system. All of the valves are electrically operated. There is a shut off valve for the hot water from engine. The temp setting decides how much water to allow to pass.  Remember your heat source (the engine) is in the back. So when you turn on the heat it will take a while for the hot water to warm the hoses, then the heat exchange, and finally the ducts before you start feeling the warm air.
Title: Re: Dash heat
Post by: oldguy on December 10, 2023, 02:11:52 pm
On my coach I leave the heat valve is on all winter but even if I didn't have in on the kind of valve
on my coach isn't an on/off valve it is a diverter valve so hot engine water is always at the valve and
when it's turned to heat it just diverts the hot water to the heater core.
Title: Re: Dash heat
Post by: oldguy on December 10, 2023, 03:26:32 pm
Bob I just went through Thermotions web site and I can't find the switch for their valve. I guess you
phoned 440-639 6325 to find out what they used to control their valve. Are you sure it is the control
switch is bad and not the motor on the valve. That was what was wrong with mine. I don't even know
how you would get at the valve. I cut a hole near the valve and the installed semi-head lights there so
I could work on it.
Title: Re: Dash heat
Post by: erniee on December 10, 2023, 05:45:07 pm
After the buck messed up the right front of my coach, I had to do some heater hose repair. One of the things the got destroyed was the valve which you control how much or how little you get hot water to your heater core. This is an electronic valve which you control by the dash knob. I would think these would fail overtime. Foretravel had the exact replacement in stock. If you pop open your generator access, and look to the left, you can see the heater hoses. Before the hoses go into the floor, that valve is right there.
I forgot what the price was, but it was cheap at any price.
Title: Re: Dash heat
Post by: oldguy on December 10, 2023, 07:30:30 pm
Thanks Ernie, I probably saw this when I was trying to trouble shoot the valve and forgot about it
as I couldn't trouble shoot the valve from there. It still looks like a bitch of a job to change it. My motor
was shot so I just changed the motor.
Title: Re: Dash heat
Post by: oldguy on December 10, 2023, 07:51:59 pm
Does anyone know who makes the dash air system.
Title: Re: Dash heat
Post by: bigdog on December 11, 2023, 06:41:56 pm
Dash heat?  What's that?  We get heat if we also run the Aqua Hot. But not much via engine heat.
Title: Re: Dash heat
Post by: Journey, Roam, Explore on December 11, 2023, 06:50:40 pm
I did call thermotion and did not get a good answer. When I sent them a photo of the part they said it wasn't theirs. The mixing valve is on the passenger side of the coach just behind and above the headlights. Since I don't have stock headlights anymore and that area is just covered with a piece of aluminum it's not incredibly hard to access. When I was at Foretravel in 2019 I was told they don't make that switch anymore or couldn't get it.