Coachman Report post Posted November 4, 2011 We have a 2008 Patriot Thunder. Turned the heater on this morning and of the 3 zones the bedroom (zone 3) did not work. The others did. All I got from zone 3 was blowing air. So the fan is working. We are on shore power (50 amps). Your thoughts would be appreciated. Thanks Share this post Link to post Share on other sites
wolfe10 Report post Posted November 4, 2011 Air blowing but not heat means that the thermostat is working and the fan is coming on. The problem may be inadequate CFM to close the SAIL SWITCH. Blocked air return, too many vents closed, crushed ducts, low voltage at the furnace are common causes. It could also be that the PC board is bad-- many RV dealers have testers for them, but start by removing the connections from the PC board and gently cleaning with an eraser. The PC board is the "brains" of the furnace. It receives the "turn on" signal from the thermostat, receives OK signal from sail switch, opens propane valve/powers igniter, etc. Listen carefully outside by the furnace when you have someone turn it on. Do you hear the IGNITER clicking? Smell propane out the exhaust (GAS VALVE opening)? Brett Share this post Link to post Share on other sites
chucknewman Report post Posted November 30, 2011 Coachman, Everything Brett posted is right on for propane forced air furnaces, but based on your model coach and your statement "and of the 3 zones the bedroom (zone 3) did not work" I suspect you have a hydronic heating system such as a AquaHot. The coolant for each zone is controlled by it's own thermostat that itself controls (via a logic board) flow solenoids in the coolant lines. The individual radiator fans are controlled by zone, via relays. The fact your fan runs but you have no heat tells me you have blocked coolant flow due to a closed valve or flow solenoid. Has anyone messed with your system lately? Chuck Share this post Link to post Share on other sites
wolfe10 Report post Posted November 30, 2011 Good point, Chuck. We don't know whether he has a propane-fueled heater or hydronic system. TOTALLY different. Please let us know AND any other diagnostic clues you have observed. Share this post Link to post Share on other sites
hermanmullins Report post Posted November 30, 2011 We have the AquaHot unit. When I last had ours serviced it was low on coolant. The coolant is a mixture of 50% H2O and Boiler Anti Freeze. The tech also changed out the injector. There is a valve for each zone on the coach. They each have their own solenoid valve. The valves stick sometime after not being used through the warmer weather. The tech showed me how to tap (Lightly) each valve with a small hammer. This will unstick the valve and it should work all winter after that. Hope my experience helps. Share this post Link to post Share on other sites
chucknewman Report post Posted November 30, 2011 As an afterthought, I should elaborate on my question "Has anyone messed with your system lately?" I had studied Webasto and AquaHot hydronic systems when we were into bus conversions. When we got the Safari it has a system from International Thermal Research out of Canada. They market mostly to marine users but installed several hundred into coaches. Our ITR Hurricane had a couple issues and I quickly found most RV "techs" don't do a lot of work on these systems and are not 100% up to speed on the technology. Fortunately, I was able to contact a person at ITR that knew the system inside and out. Plus he put me onto their excellent website of documentation and instructional videos. The point being in my system and other's I've helped with, RV "techs" have installed wrong size fuses, left valves closed that should have been re-opened after troubleshooting, etc. And tapping solenoid valves to get them to work? That's just mediocre folks. But it is life in the RV world. I highly recommend you call or check the hydronic manufacturer's web site to locate a factory trained and qualified technician to service/repair your system. Chuck Share this post Link to post Share on other sites
