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HenryG · 12-03-2010, 12:43 PM

Hello

I have a 26 Overlander 1976 that has been restored in a trailer park.
I don't trailer it as such.
It is used as a fishing and summer getaway.
Everything works on my tin can and that was surprising when I got considering it had sat around for 10 years.
Changed a few things and it works like it would have in 1976.

Here is my dilemma.
On cold evenings, I set the thermostat to 68, let it run until it is cozy in the trailer, then turn the thermostat off for the night's sleep. I don't worry about CO poisoning because I do it this way.

I have a great sleeping bag that keeps me warm all night. In the morning, I need to get out of the sleeping bag and physically go to the thermostat to turn it on. BRRRRRRRRRR Then go back to bed to await heat so it's a smooth transition from sleeping bag to warm trailer.

So I checked out the schematics for the original NT 32 A furnace , bought a remote control kit on line and tried to install it, so that on those cold mornings, all I would do is have the thermostat set at 68 , press start on the remote and the furnace would warm this up nicely to allow me to get out of my sleeping bag without freezing to death. I couldn't get it to turn the furnace on and off where I tried to install the wires.
The remote control can be found online and is LOGYSIS 12 volt Remote(model rm02) with 15 amp max.
It has power- a (red) in and a (red) out as well as 2 ground (black)wires along with a (blue) remote receiver wire.

Any ideas as to where to install the wiring for this thing, so it can serve as a remote switch for the furnace, both in the evening to turn it off and in the morning to turn it on, would be appreciated.
Thanks in advance.
Am I being selfish for wanting a smooth transition in the morning????????

HenryG

easyride · 12-03-2010, 12:51 PM

Aren`t you worried about the pipes freezing,while you are all cozy in your sleeping bag.
Think I would would turn it down a little more just to keep the pipes warm,unless you are dry camping. Dave

HenryG · 12-03-2010, 01:06 PM

The trailer has been winterized at this point which means no water in lines anywhere in the trailer. Thanks for the concern though.
Only power in the park is what I provide with batteries and I have 6 in unison so lots of 12 volt power.
It's strictly a fishing trailer this time of year in Sarnia Ontario and I go for a couple of days at a time, fish and then come home.

I'd rather avoid the noise of the furnace cycling on and off and certainly the CO poisoning potential at night. I have CO detectors that function.

Any ideas on the wiring location?

HenryG

Bauxter · 12-03-2010, 02:25 PM

I personally would want to switch off the low voltage coming out of the thermostat to the furnace, and let the furnace controls work as normal. The device would then work as an additional low voltage on/off control. You could place the device next to the furnace under the sink, and hook it up to the thermostat lines going into the furnace....assuming you have the same type and placement of furnace as mine.

HenryG · 12-04-2010, 08:14 AM

Thanks Bauxter

I see what you are saying about not interrupting the thermostat operation.

I'll give your idea a try. I have an inline fuse attached to the remote control wires so as not to destry it in case wires get mixed up.

I called Suburban and spoke to a technician there who hadn't heard about doing this kind of thing before but said that it was a workable solution to my problem.

He suggested placing it on the wire going into the thermostat so that the thermostat gets powered when the remote switch is turned on and the thermostat functions normally ---until I turn it iff for the night.

May try both ideas to see which works better.

HenryG

Bauxter · 12-06-2010, 07:07 AM

I never really liked shutting off a burner and the fan at the same time, which is the result of remote switching the power off. If you power down the low voltage thermostat line going to the furnace, the fan should continue to run until the heat level in the exchanger is below a certain temperature. Also, you will pull all of the heat from the furnace that was created by that expensive propane.

ck21084 · 12-06-2010, 07:46 AM

I agree you should switch the supply voltage to the thermostat. I am not familiar with the voltage used but does your device use separate power for supply and control? If so this might work, if not you will have install a relay that this remote device would control.

If some one knows the voltage of the thermostat wires I can draw you a schematic.

Jammer · 12-06-2010, 08:34 AM

The problem with doing this is twofold. First, the wiring of furnaces varies slightly among models. Second, the wiring to the thermostat is not color coded as to which side is the +12v supply and which is the switched control.

The remote control you're using doesn't have a "dry contact" output, which is what you actually need. Instead it has a switched +12v output.

If I were going to set something like that up I'd use a relay, as ck21084 suggests, with the contacts in series with the thermostat, and the coil driven by the remote control. This does add to the phantom load which would be a concern if you're boondocking.

You might find that it's easier to just put a switch somewhere close to the bed where you can reach it, and wire that in series.

CO should not be a concern from an RV furnace. They have a heat exchanger that isolates the burner from the interior air. If the condition of the heat exchanger is in doubt, you should inspect it and replace the furnace if it has holes in it.

ventport · 12-06-2010, 08:50 AM

Jammer is correct, the remote you are looking at turns on and off 12 volts. You would need in addition to the remote a 12 volt relay with isolated contacts that were not powered. The contacts would be wired into one of the thermostat wires, it will not matter which one. Or cut one of the thermostat wires and connect a 2 wire cable to each of the just cut wires and run the cable to a switch near your bed. Then you could turn the thermostat on and off from the bed and the fan would cycle according to the heat in the furnace as was intended by the manufacturer.

blickcd · 12-06-2010, 10:23 AM

Is there any chance that just a basic programable thermostat could be used?

Christopher

ck21084 · 12-06-2010, 11:40 AM

I think that it could because the cheaper ones are just a relay. You would have to make sure that it provieded its own power via batteries and to follow the KISS idea you could use the fan contacts only.

HenryG · 12-06-2010, 05:51 PM

Thankyou for the interest in my project and the great suggestions.

I have volt metred both white wires that connect to the thermostat but need to do more testing.

I have connected the red in and red out wires to one of the white wires leading to the thermostat---result was nothing happened. Everything worked fine after reconnection. There was not grounding on the 2 black wires which I never tried but will in a future trip to the trailer. Currently snow storms hitting Goderich Ontario!

The programable thermostat idea might work as a possible option--thanks for the suggestion.

That whole idea of a simple wired switch may be a last resort if this remote doesn't work.

The relay idea has my interest peaked but I am not thoroughly electrically knowledgeable.
Jammer----Can you explain further based on the 2 white wires and the thermostat and my remote (2 red power wires in/out---2 black ground wires--and blue receiver)

"If I were going to set something like that up I'd use a relay, as ck21084 suggests, with the contacts in series with the thermostat, and the coil driven by the remote control." ????

HenryG

Jammer · 12-06-2010, 09:08 PM

Relays have two connections for the magnetic coil and two or more (often many) connections for the switched contacts.

Get a suitably rated relay and socket. Like these:

Automotive Relays for 12 Volt DC Circuits

One coil wire (they're the smaller diameter ones) goes to ground, one to the red "power out" on your remote.

Turn the remote on and off. Do you get satisfying click noises from the relay? Good.

Cut one of the white wires to the thermostat, connect one cut end to one of the three big wires on the socket, and the other cut end to a different big wire. Turn thermostat up to 90 degrees, and see if the remote turns the furnace on and off. If not, try using a different pair of big wires. There are three ways to hook it up, two of them are wrong (one of them is backwards, so on is off and off is on, but maybe that's ok) and most days it's easier to just see which one works the way you want than to try and figure it out.