PT-42 Front Heaters

[Pete Masterson]

1. Front thermostat (above driver's head) only controls the AC. When
set to 'gas heat' it doesnt' do anything. I have the vents you
describe, and nothing I've tried causes them to do anything. I, too,
can not find (feel) any heater core or other heating element behind
them. My supposition is that the vents are to allow air circulation
to the components behind the dash -- nothing more. (Indeed, it would
be great to have a little heat in that area while parked... but it
doesn't seem to be the case. I suppose you could turn on the 'engine
preheat' switch (board above driver's head) which turns on a pump
from the AquaHot to heat the engine so then you'd get some heat
through the chassis system -- but I expect that would be subject to a
_lot_ of waste and neither be economical or effective.)

The AquaHot heater core under the sofa is very effective. It's
controlled by the center thermostat. (Dash AC switch on, power switch
on thermostat on, second switch on thermostat to 'gas heat' and set
temperature according to your desire.) This same thermostat also
controls the AH heater core located under the galley cabinet. A
square Robert Shaw thermostat next to the Dometic thermostat controls
the electric Perfectoe heater under the galley.

The AquaHot system in the '95 is set up with 3 heating loops. One to
the bedroom, another to the bathroom, and the third to the forward
area with the heater cores under the sofa and galley cabinets. One of
these loops (I'm not sure which one) also 'feeds' the basement heat
system that has cores located in strategic places (such as one aimed
right at the domestic water pump) and is controlled by a 'low
temperature' thermostat on the front basement bulkhead on the curb
side. It allows settings as low as 40. I've used it in temperatures
down to 15 degrees and it seems to work as I haven't had any freezing
problems in the basement. All of the AquaHot heater cores have small
"pancake" 12 v fans to move air through the heater core. One service
check is to turn on the heat and check to see that the fans are
working. (In my coach, the fans under the kitchen cabinets are a
trifle noisy, but they move a goodly amount of air. The other fans
have modest noise when operating, but aren't too intrusive.)

2. My control lever requires moderate effort -- and the passage from
left to right (or right to left) has 'sticky' spots. I'd guess a
spray silicone lubricant if you can reach any of the cable or other
components. I haven't tried to get to them, yet. (see next)

I'm sad to report that I do have one problem with the chassis system.
There's a "door" deep in side that's supposed to move when the AC
goes on ... unfortunately, it's not moving when it's supposed to. The
most noticeable symptom is that the amount of air coming from the
'eyeball' vent isn't very significant. The door was working when I
first got the coach, but quit sometime last year. If anybody had any
ideas on how to get to the internal workings of the vent system, I'd
appreciate any suggestions.

Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
aeonix1@...
On the road at Lockhart Texas



On Nov 21, 2007, at 6:51 PM, bumpersbird wrote:

> '95 PT-42 Front Heater Question
>
> 1 - Ok I have dash heat and air like in any car or truck. But I also
> have three vents on the bottom of the front consol, near the step
> well. I thought that the thermostat that controls the front air would
> operate one these vents, like the two thermostats in the kitchen and
> bedroom, they operate the hydronic heat and A/C in those areas, but
> it doesn't. The dash A/C – Heater operates the two floor vents over
> the step well. But the third larger vent, more or less amid ship,
> doesn't seem to do anything. I got my hand up in there behind it,
> though the CB compartment and I couldn't feel any heater core of any
> kind, or much of anything else for that matter. It might be like the
> vents over the step well the heat just dumps into the consol area and
> kind of pushes its way through the vents. Any help would be great! I
> was told when I bought the coach that there is no heat up front when
> the coach is in camper mode, only when the engine is running. If
> anyone is curious there is a heater just under the sofa up front near
> the drivers chair and it does a great job. I would just like one near
> the door to offset heat loss when the family is going in and out 50
> times a day.
>
> 2 - Also the temperature control slider on the dash is very difficult
> to operate. I'm afraid that I will break it; it takes that much force
> to slide left or right. I know the cable and hinges need to be lubed,
> but I'm not sure what to use for lube. WD-40 need not respond;}
>