Heater question

[Majja13]

This is a proxey question for my neighbor. They have a Jayco Kiwi that the heater will come on sometimes and not others. It sounds like a bad thermal couple to me. I am not sure where to look to see what is wrong. I would like to help them fix it just not sure where to start. Any suggestions would be great. It has power and Propane. the heater is turned and the thermostat in raised to a level higher than the temp so it should turn on.

Thanks
Majja

[Shavano]

Moved to Tech Issues
Moderator- TT's

[Golden_HVAC]

bfever74 wrote:
Thermocouples are $8. I would just throw one in it. It can't hurt. The only way to check them is to use a voltmeter and apply heat and measure the differnce in voltage from hot to cold.

Or like I said, they are $8. 🙂

The new thermocouple will work great if the trailer is 1980 or older, and you have to light the pilot manually with a match. Newer models that have self-ignition do not have a "Thermocouple". They would have a flame sensor, and cleaning it will sometimes let it work properly.

Sometimes just unplugging the flame sensor, and plug it back in, will remove enough corossion from the terminal that it will work for a few more years.

Many times I find people report "The furnace worked great on the first night, and while driving to the campground. But that second night, only the fan would run, and the third morning, the battery was dead, nothing worked then. "

The problem in some cases is that the voltage falls below about 11.5 volts, and then the fan is not running fast enough to close the fan safety switch, and allow the flame to come on. A full battery with no load on it should be at 12.8 volts. Below 11.5, you can damage the battery plates if you continue to discharge it.

So if you are plugged in, and the battery meter reads 13.0 volts or higher, or the battery gauge reads "Full", you should have enough voltage, the fan should be spinning the correct speed.

If the proble only happens when dry camping, (without power) I would suggest turning on the generator the next time, and see if the furnace works great on shore power or generator power, but only messes up while on battery power, in that case, I would suspect low battery water level, to small battery pack, or the charger not fully filling the battery.

You can test the trailer at home, just unplug for a hour, test the furnace (battery should be full, it should work great), then leave on some lights, say 10 of them will draw about 12 - 15 amps per hour for about 1.5 hours, and test the furnace again. IF it stops working before the 10 lights have run about 4 hours, then the battery capacity is either to small, or the battery might be worn out.

Fred.

[Majja13]

I will find out more. Dawn just was over at the house telling me about it. And asking if I could help. I told her about this site, maybe I can get her to register and post all of the symptoms on this thread.

[bid_time]

What are the symptons, does the thermostat make contact, does fan come on, does the sail switch come on, does the ignitor come on, does the pilot light come on, does the valve open, does the flame come on, is the gas turend on? You need a little information before you start throwing money at things to see what works. Read up on how the furnace works on the net then you can figure out where the break in the chain of actions is. My guess is you just need to clean the "flame proofer" (90% of the time that fixes furnace problems), but that is only a guess without any symptons.

[bfever74]

Thermocouples are $8. I would just throw one in it. It can't hurt. The only way to check them is to use a voltmeter and apply heat and measure the differnce in voltage from hot to cold.

Or like I said, they are $8. 🙂

[donn0128]

First thing I would do is open the thermostat and determine which wires need to be powered for the heater to fire and using a small jumper jump between 12VDC plus and heater on and see what happens. Sounds like a bad thermostat to me.