Community Forums

Smsudad · 11-14-2013, 01:49 PM

Hi all, I have a 2006 allegro 28 foot it has two a/c and two furnace switches one for the front and another in the bedroom for the rear. Both are on the thermostats. When I set the front one on heat and slide the temp up it triggers the fan on and the furnace starts, when I turn the rear one on and slide the temp up I hear the click near the A/C but nothing else happens...... No fan turns on and no heater noises. I was to understand that the rear heat is the one that heats the water tanks but I'm not sure, also not sure if it's working properly. Any help will be awesome. Thanks.

Gocoffeer · 11-14-2013, 02:44 PM

SMSUDAD... you handi with an OHMMETER? If you are for the most part you can diagnosis or eliminate many of the gas heat system issues an RV might have. This leads to either adjustment or parts swapping. Often getting to the issue is harder than diagnosing it. If you are ready I will indeed release the simple YOU TUBE RV Furnace diagnosis and troubleshoot videos. You must be the Allegro expert and locate your hardware since I am not familiar with your model.

Smsudad · 11-14-2013, 02:57 PM

Gocoffeer, Thanks. Yes I would be delighted to find the issue, I have ohm meter in hand.

Rocky Larson · 11-14-2013, 05:37 PM

I am not sure what your set up is? Your rear ducted roof A/C should just be A/C only. Your front A/C had an option of heat pump so maybe both A/C and Ducted heat. I don't think Tiffin supplied dual heat pumps in the 2006 DA. Also I would only expect one propane furnace which is floor ducted and supplies heat to the holding tanks. Thats the way it is on my 30DA. YMMV.

Gocoffeer · 11-15-2013, 06:49 AM

RV Furnace Maintenance - Do It Yourself - YouTube

SMSUDAD....here is a nice video for the start of this adventure. I will add more to your review throughout the day.

Gocoffeer · 11-15-2013, 06:53 AM

SMSUDAD...here is a model I am familiar with.... notice a common thought between both videos...corrosion and decay in the wire harness connector. When I worked on my furnace this is where i found my issue.

RV Gas Furnace Service Demonstration - YouTube

luvlabs · 11-15-2013, 11:03 AM

I believe you only have a single furnace. You rear thermostat is for cooling only. Take a walk around your coach and see if you can find a second furnace - I believe you are only going to find the one.

62Morgan · 11-22-2013, 12:17 PM

Not in answer to your inquiry, but helpful nevertheless to those who have not not yet discovered it:

The t'stat operation is well-known to trigger the furnace operation [even if you selected the heat pump mode] because if you choose a desired temp setting in excess of 3-5 degrees above the current temp, it will call for the furnace to operate in an effort to hurry-up the comfort heat level. Once the furnace reaches the desired temp, it will allow the heat-pump to maintain your setting. You can avoid triggering the furnace by stair-stepping the temp setting by 3 degrees at a time.

jeepfreak · 11-22-2013, 02:39 PM

We have a 07 35 ft and it has 2 a/c's front with a heat pump and 1 lp furnace. The rear t-stat does have a heat setting but does nothing as there is no heat for it to control.

62Morgan · 11-25-2013, 06:31 AM

jeepfreak, on your 34 foot coach...doesn't your rear heat setting control the heating cycle of the bedroom heat-pump? Even if there is no 2nd furnace unit, you should still have rear bedroom heating method via the heat-pump on the roof. I can see the shorter 28 foot coach having only one heat-pump; but your length should have both rooftops as heat-pumps.

jeepfreak · 11-25-2013, 08:51 AM

My coach came with only one heat pump and it's the front unit , the bedroom unit is a/c only.

herbc · 01-24-2014, 08:24 AM

Hello,
I was looking for something to resolve my heat pump problem when I ran across this topic. I have a 2003 37DB Allegro Bay. It has one thermostat that controls the front and rear heat pumps and "both LP furnaces". Although there is only one thermostat it does control everything. I can only presume the sensor for the bedroom is located somewhere in the bedroom. The comments above about the furnace coming on when heat pump is selected may have answered my question as I set it for heat pump and the furnace came on. Now I will set the temps closer to the inside temp to see if the heat pump comes on. Hope this helps others.

Herb

herbc · 01-31-2014, 06:05 PM

Well, I contacted Dometic and they sent me a manual. If the thermostat senses too much of a differential between what the inside temperature is and what the thermostat is calling for the LP furnace will come on first to bring the temp within range so the heat pump can handle it. All in the thermostat. Quite a setup. I was surprised when this happened on my rig but it is normal. Hope this helps.

Herb

sbranen · 03-02-2014, 08:47 PM

When you want to use your heat pump, check your interior temperature and then add no more than about 4 degrees to that number. Now set your upper limit set temperature on your thermostat and it should work perfectly every time when you turn your heat pump on. When your room temperature has reached the set point temperature and your heat pump shuts off, do the same thing again. Note your existing temperature and add another 4 degrees again to your your new set point temperature. Works for me.