Community Forums

rvtips · 03-29-2011, 11:36 PM

On our 2003 safari with the ISC350 motor,we don't get much heat from the heater.the water temp. is 185. I read some where that there are valves to turn off the coolant, that at times can turn them self off or reduce the flow.
I have found the one that turns off the flow to the coolant filter but can't find any others?

HeapBigEngin · 03-30-2011, 01:35 PM

On our F/wood Revolution with Cummins 8.3 ISC and side mount radiator, both valves are reachable on the driver side of the engine. The lower one is pretty obvious since is it close to the radiator plumbling. The other one is up above, at the front (toward the front of the coach) of the engine near/at the cyclinder head. You have to get under the coach and look up there to find it....and it is there. The one that could vibrate and partially close was the lower one. By the way, at 185 degrees (and considering how far that coolant has to flow, the heat coming out of the vents is not scorching hot....but it should be very, very warm.

Since our coach does not have a pull-out generator, I have a hood that opens which reveals the gen set below AND the coolant hoses and stuff. At 195 degress (where our coach operates), those hoses are hot. Of course, the cooler outside air blowing over the heater core will lower the temp somewhat. Hope that helps. There could be something else lurking there causing the problem....blend door not closing properly, cable binding up, etc. If the valves are open and the heat is only luke warm, perhaps someone else here can provide some help. Please let us know what you find....thanks!

NITEHAWK · 03-30-2011, 01:53 PM

Our Foretravel Grand Villa has a valve accessable thru the opening under the sink and behind the ice maker. If it is not turned off the engine coolant circulates around the water heater to preheat the water while traveling. Shut the valve and the heat goes up front instead. Possibly your coach has a similar arrangement.

mahon1993 · 03-30-2011, 02:18 PM

Depending on the type of dash heater controls you have, you could have a problem with the heater control valve. Mine has a servo-controlled valve mounted right next to the heater core accessable thru the generator front hood. It's on the passenger side in the upper left. The valve has a by-pass function to keep the coolant flowing when it's turned off. If it is not opening up all the way you will not get enough heat. I had water dripping on the electrical connector of mine causing not to open all the way. I think there are 4 or so wires on the connector. Make sure they are clean.
Greg

rvtips · 03-30-2011, 04:59 PM

Today I called Monaco tech and he said there is NO valves to turn off or on only the one for the coolant filter.
He said to check the heater control valve,I will do that next.

Quote:

Originally Posted by heapbigengin

On our F/wood Revolution with Cummins 8.3 ISC and side mount radiator, both valves are reachable on the driver side of the engine. The lower one is pretty obvious since is it close to the radiator plumbling. The other one is up above, at the front (toward the front of the coach) of the engine near/at the cyclinder head. You have to get under the coach and look up there to find it....and it is there. The one that could vibrate and partially close was the lower one. By the way, at 185 degrees (and considering how far that coolant has to flow, the heat coming out of the vents is not scorching hot....but it should be very, very warm.

Since our coach does not have a pull-out generator, I have a hood that opens which reveals the gen set below AND the coolant hoses and stuff. At 195 degress (where our coach operates), those hoses are hot. Of course, the cooler outside air blowing over the heater core will lower the temp somewhat. Hope that helps. There could be something else lurking there causing the problem....blend door not closing properly, cable binding up, etc. If the valves are open and the heat is only luke warm, perhaps someone else here can provide some help. Please let us know what you find....thanks!

Tha_Rooster · 03-30-2011, 05:37 PM

Do you have a recirculate air button if you so your air will get warmer.

HeapBigEngin · 03-30-2011, 11:14 PM

Quote:

Originally Posted by rvtips

Today I called Monaco tech and he said there is NO valves to turn off or on only the one for the coolant filter.
He said to check the heater control valve,I will do that next.

Not sure about Monaco MH's. Our F/Wood (on a Freightliner chasis) has the 2 valves as I described in my ealier post. Yours must be plumbed differently. Not sure why Monaco would not have the valves. Seems that if the front heater core or the attached hoses & clamps started leaking, it would help if the heater system and coolant could be "shut off" from the engine's cooling system to prevent coolant loss. That exact thing happened to us last summer. Glad I found those two valves on one of our trips last summer 'cause one of the several hoses attached to the heater core inside the coach decided to go south....just as we were going north, still 60 miles from home. Not a happy scene!!

Sounds like it is more likely to be something up front like mahon1993 mentioned. Please let us know what you find out.....Thanks much!