Wall thermostat problem

[Scott Forman]

I have a problem in one of my wall thermostats. The one in the bedroom
that controls the propane furnace and chassis heat will work fine for
some period of time, but sooner or later (usually sometime overnight
while I am asleep), it quits shutting off and the heater runs
continuously. While I guess I could just consider it a sauna, I'd
really like to fix it instead. Any ideas what might cause this?

Scott Forman
86 PT38
Memphis

[Curt Sprenger]

Scott,
Replace the theromostat with a digital unit. I'm going to do the same.

On Dec 8, 2007 7:52 PM, Scott Forman <sforman@...> wrote:

> I have a problem in one of my wall thermostats. The one in the bedroom
> that controls the propane furnace and chassis heat will work fine for
> some period of time, but sooner or later (usually sometime overnight
> while I am asleep), it quits shutting off and the heater runs
> continuously. While I guess I could just consider it a sauna, I'd
> really like to fix it instead. Any ideas what might cause this?
>
> Scott Forman
> 86 PT38
> Memphis
>
>
>



--
Curt Sprenger
1987 PT38 8V92 "MacAttack Racing"
Anaheim Hills, CA


[Non-text portions of this message have been removed]

[Gregory OConnor]

Curt will the digital maintain memory with the transfer switch? or
park power outage? I remember someone posting that they leave one a/c
stat murcury to keep one zone on if they are away from the bus during
the day and there is a momentary park poweroutage????

GregoryO'Connor
94ptRomolandCa

--- In WanderlodgeForum@yahoogroups.com, "Curt Sprenger"
wrote:
>
> Scott,
> Replace the theromostat with a digital unit. I'm going to do the
same.
>
> On Dec 8, 2007 7:52 PM, Scott Forman <sforman@...> wrote:
>
> > I have a problem in one of my wall thermostats. The one in the
bedroom
> > that controls the propane furnace and chassis heat will work fine
for
> > some period of time, but sooner or later (usually sometime
overnight
> > while I am asleep), it quits shutting off and the heater runs
> > continuously. While I guess I could just consider it a sauna, I'd
> > really like to fix it instead. Any ideas what might cause this?
> >
> > Scott Forman
> > 86 PT38
> > Memphis
> >
> >
> >
>
>
>
> --
> Curt Sprenger
> 1987 PT38 8V92 "MacAttack Racing"
> Anaheim Hills, CA
>
>
> [Non-text portions of this message have been removed]
>

[erniecarpet@...]

Mine does the same- about froze a couple weeks, ago. Let us know what kind
of thermostat you come up with.

Ernie Ekberg
83PT40
Weatherford, Tx




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[Non-text portions of this message have been removed]

[Gardner Yeaw]

I don't know what's wrong with using a simple mechanical
thermostat. It's cheap and does the job. Maybe in my home where I
want it to have several settings throughout the day/week, but in the
RV it's much simpler to set it by hand.

Gardner
78FC33

--- In WanderlodgeForum@yahoogroups.com, "Gregory OConnor"
wrote:
>
> Curt will the digital maintain memory with the transfer switch? or
> park power outage? I remember someone posting that they leave one
a/c
> stat murcury to keep one zone on if they are away from the bus
during
> the day and there is a momentary park poweroutage????
>
> GregoryO'Connor
> 94ptRomolandCa
>
> --- In WanderlodgeForum@yahoogroups.com, "Curt Sprenger"
> wrote:
> >
> > Scott,
> > Replace the theromostat with a digital unit. I'm going to do the
> same.
> >
> > On Dec 8, 2007 7:52 PM, Scott Forman <sforman@> wrote:
> >
> > > I have a problem in one of my wall thermostats. The one in
the
> bedroom
> > > that controls the propane furnace and chassis heat will work
fine
> for
> > > some period of time, but sooner or later (usually sometime
> overnight
> > > while I am asleep), it quits shutting off and the heater runs
> > > continuously. While I guess I could just consider it a sauna,
I'd
> > > really like to fix it instead. Any ideas what might cause this?
> > >
> > > Scott Forman
> > > 86 PT38
> > > Memphis
> > >
> > >
> > >
> >
> >
> >
> > --
> > Curt Sprenger
> > 1987 PT38 8V92 "MacAttack Racing"
> > Anaheim Hills, CA
> >
> >
> > [Non-text portions of this message have been removed]
> >
>

[Don Bradner]

The Hunter digitals usually used to replace the mercury units are battery
powered, so yes, they retain their memory. In the 90 Bird, the original
thermostats are a mixture - mercury for the heat, but digital for the A/C. Those
digitals are A/C powered, and while they maintain memory, they revert to an off
condition when there is momentary power loss. I intended to replace one of
those, but instead opted for an in-shroud control when replacing an A/C.

Gardner, the point of the digitals isn't for things like weekend differences -
the digitals most use don't offer such "features." The points are: easy
precision setting, low precise hysteresis, and no issues of contact sticking.
The mercuries I replaced had high and variable hysteresis, in one case more than
10 degrees between off and on.

The Hunter 42999B is cheap, easy to install, and easy to use. Wal-Mart is common
source in the $20 range. The thermostat manual can be seen at
http://www.hunterfanhq.com/tools/sales/h...42999b.pdf
or http://tinyurl.com/2g47pv

On 12/9/2007 at 6:05 AM Gregory OConnor wrote:

>Curt will the digital maintain memory with the transfer switch? or
>park power outage? I remember someone posting that they leave one a/c
>stat murcury to keep one zone on if they are away from the bus during
>the day and there is a momentary park poweroutage????
>
>GregoryO'Connor
>94ptRomolandCa
>
>--- In WanderlodgeForum@yahoogroups.com, "Curt Sprenger"
> wrote:
>>
>> Scott,
>> Replace the theromostat with a digital unit. I'm going to do the
>same.

[Scott Forman]

Is replacing the thermostat straightforward? I haven't pulled mine
off to investigate, but since that one unit controls propane heat,
chassis heat, and the exhaust fan in the bedroom, I wondered if it
might be more complicated than a normal one.

Scott

--- In WanderlodgeForum@yahoogroups.com, "Curt Sprenger"
wrote:
>
> Scott,
> Replace the theromostat with a digital unit. I'm going to do the
same.
>
> On Dec 8, 2007 7:52 PM, Scott Forman <sforman@...> wrote:
>
> > I have a problem in one of my wall thermostats. The one in the
bedroom
> > that controls the propane furnace and chassis heat will work fine
for
> > some period of time, but sooner or later (usually sometime
overnight
> > while I am asleep), it quits shutting off and the heater runs
> > continuously. While I guess I could just consider it a sauna, I'd
> > really like to fix it instead. Any ideas what might cause this?
> >
> > Scott Forman
> > 86 PT38
> > Memphis
> >
> >
> >
>
>
>
> --
> Curt Sprenger
> 1987 PT38 8V92 "MacAttack Racing"
> Anaheim Hills, CA
>
>
> [Non-text portions of this message have been removed]
>

[Don Bradner]

Shouldn't be difficult. One of the ones I replaced controls propane furnace,
electric heat, and exhaust fan. In heat mode it controls either furnace or
heater depending on the setting of an existing/remaining switch. In cool mode it
controls the fan. In fan mode the fan can be manually turned on/off. All normal.

On 12/9/2007 at 5:03 PM Scott Forman wrote:

>Is replacing the thermostat straightforward? I haven't pulled mine
>off to investigate, but since that one unit controls propane heat,
>chassis heat, and the exhaust fan in the bedroom, I wondered if it
>might be more complicated than a normal one.
>
>Scott
>
>--- In WanderlodgeForum@yahoogroups.com, "Curt Sprenger"
> wrote:
>>
>> Scott,
>> Replace the theromostat with a digital unit. I'm going to do the
>same.

[Gardner Yeaw]

Don,
Thanks for the response. I guess I'm getting old and just don't
trust the new fangeled 'digital' things. But really, thanks for the
explanation. My original units do seem to have a mind of their own.
The unique "boyoiyoing" sound when it shuts off is always a
reasurance during the night that it is working, and it wakes you up
just to be sure you are paying attention.

Gardner
78FC33

--- In WanderlodgeForum@yahoogroups.com, "Don Bradner"
wrote:
>
> The Hunter digitals usually used to replace the mercury units are
battery powered, so yes, they retain their memory. In the 90 Bird,
the original thermostats are a mixture - mercury for the heat, but
digital for the A/C. Those digitals are A/C powered, and while they
maintain memory, they revert to an off condition when there is
momentary power loss. I intended to replace one of those, but
instead opted for an in-shroud control when replacing an A/C.
>
> Gardner, the point of the digitals isn't for things like weekend
differences - the digitals most use don't offer such "features." The
points are: easy precision setting, low precise hysteresis, and no
issues of contact sticking. The mercuries I replaced had high and
variable hysteresis, in one case more than 10 degrees between off
and on.
>
> The Hunter 42999B is cheap, easy to install, and easy to use. Wal-
Mart is common source in the $20 range. The thermostat manual can be
seen at
http://www.hunterfanhq.com/tools/sales/h...ges/owners
/42999b.pdf or http://tinyurl.com/2g47pv
>
> On 12/9/2007 at 6:05 AM Gregory OConnor wrote:
>
> >Curt will the digital maintain memory with the transfer switch?
or
> >park power outage? I remember someone posting that they leave one
a/c
> >stat murcury to keep one zone on if they are away from the bus
during
> >the day and there is a momentary park poweroutage????
> >
> >GregoryO'Connor
> >94ptRomolandCa
> >
> >--- In WanderlodgeForum@yahoogroups.com, "Curt Sprenger"
> > wrote:
> >>
> >> Scott,
> >> Replace the theromostat with a digital unit. I'm going to do
the
> >same.
>

[Pete Masterson]

Does anyone know if the Hunter (or some other digital) can replace
the Dometic thermostats used for both AC and hydronic heat in my '95?
They appear to be analog/digital ... the temperature lever is a
rheostat (?) that slides back and forth (and isn't very precise) but
I see no moving parts inside the box -- just a circuit board. I was
hoping there was a control for the hysteresis (temperature lag) --
but there's none I can identify.

My issue with the thermostat is only with the heat -- it seems to
have a too narrow temperature range. For example, I like to keep the
bedroom cool for sleeping (around 60-62) if weather permits, but the
thermostat will cycle on for 15 seconds, then off for 15 seconds,
then on for 15 seconds, etc. I can get used to the fan noise (it's
not _that_ loud) but the constant on-off-on-off wakes me up and
drives me nuts. I wouldn't mind _more_ hysteresis so that heat would
run on for at least a few minutes before it cycles off for several
more minutes.

Anyone else have this issue? Any ideas?

Thanks.

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



On Dec 9, 2007, at 10:03 AM, Don Bradner wrote:
<snip>
> The point of the digitals isn't for things like weekend differences
> - the digitals most use don't offer such "features." The points
> are: easy precision setting, low precise hysteresis, and no issues
> of contact sticking. The mercuries I replaced had high and variable
> hysteresis, in one case more than 10 degrees between off and on.
>
> The Hunter 42999B is cheap, easy to install, and easy to use. Wal-
> Mart is common source in the $20 range. The thermostat manual can
> be seen at http://www.hunterfanhq.com/tools/sales/h...preseason/
> images/owners/42999b.pdf or http://tinyurl.com/2g47pv