Heater

[krsnyder]

2006 Beaver Monterey. We've been staying on the Oregon Coast for the past 4 days. It's very cold. We've been using our furnace at night. This morning I tried to turn it on and nothing happened. Hydro Hot works fine. Heat pump air conditioning and fans all work. When I turn it to Furnace, nothing! I found a trouble shooting PDF that was posted earlier that talks about re-setting the control. Did that, still doesn't work. Any ideas?

[Steve Huber Co-Admin]

Kevin,
The heat pumps won't be very effective if the outdoor temp is 40 or below. If the hydro hot is running on diesel and heating water, either the t'stats aren't sending a signal to the HH, the circulation pumps aren't working, or the fans aren't turning on. When set to furnace and HH  running, feel to see if the lines coming to the fans are hot. If so the circultation pumps are working and the fans aren't turning on. They do take awhile to engage after the furnace is on.
Steve

[krsnyder]

Temps are in the 50's cold for a desert rat!!! The lines coming to the fans are cold. Does that mean it is a Hydro Hot problem.

[David T. Richelderfer]

If the HH exhaust is hot, then it's very likely running properly.  If the lines to the furnace blowers are cold, then the problem is probably a pump is not running to move the hot coolant from the HH to the furnace/s - could be a faulty pump/s, faulty wiring to/from the pump/s, blown fuse that services the pumps, faulty valve maybe, etc.

[Joel Ashley]

Are there any red lamps on the HHot control box on the HHot bay wall, Kevin?  If so, try resetting things again by turning off the diesel switch in your galley, waiting a minute, and turning it back on.

Also as I recall, some here have merely gently hammered on a plugged cantankerous pump to clear it.  But I’ll leave that to their detailed advice as it requires removing the shroud and such, and though I know the pumps are up front under there and easy to get at, I’ve personally never had to try it.  It’s also unlikely that both interior zones (pumps) would be plugged.

Joel

[krsnyder]

Thanks for getting back. No red lights. HH is working fine. Pulled the cover off and hammered what I thought would be the valves. Still doesn't work. I'll have it serviced at my next stop. Thanks for the help.

[Gerald Farris]

Kevin,
If your HH is heating water OK, but the lines to your heat exchangers are cold and the heater fans are blowing cold air. You have either a stuck check valve (gentle rap with a hammer usually fixes that), or you have a bad pump. The strange thing is that you have 2 or 3 zones in your coach, so at least one zone should be heating if it is a pump or check valve. Have you checked all zones for heat output?

Gerald

[Joel Ashley]

The two round-faced circulation pumps are bottom left as you open the cover.  Yes, it would be unusual for both check valves to clog at the same time.  As a side note, on the control panel is the Low Temp Cutoff lamp illuminated or not?  Antifreeze up to level?

Also see this document page 85:  http://www.rvtechlibrary.com/heatair/hydronic_tips.php

Joel