No Dash Heat After Replacing Heater Control Valve on 2007 Gulfstream Crescendo

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Hello, hoping someone can help. The previous owner of my 2007 Gulfstream Crescendo with the Cummings engine, bypassed the electrical on off valve and put a regular valve in. I purchased a new electrical on off valve and installed it. Ever since I have had no heat up to the front dash. During my service in August I had them drop the antifreeze, flush it and refill it and I still have no dash heat. Had them do it a second time because we thought it might have an air block but still no change. Has anyone else had this problem and if so, how did you fix it? Thanks in advance!

 

[THenne1713]

Verify valve opens? Can also be LOW flow, i.e. clogged heater coil/ pinched/ twisted hose? Or valve was good but fuse or switch was never putting power to valve? Is Switch continuous ON/OFF, or momentary M-O-M w/ reverse polarity? I have personally never seen / never heard of electric valves on RV

 

[[email protected]]

Verify valve opens? Can also be LOW flow, i.e. clogged heater coil/ pinched/ twisted hose? Or valve was good but fuse or switch was never putting power to valve? Is Switch continuous ON/OFF, or momentary M-O-M w/ reverse polarity? I have personally never seen / never heard of electric valves on RV

I was a mechanic for 25 years and have checked all the above you mentioned. The new elec valve works fine, I tested it prior to installation. The old one would not work when voltage applied through the control panel. The heat worked prior as the old guy had it bypassed with manual valve under the hood. My tests point to an air block possibly but I had a professional truck shop drop the antifreeze and redo it and still have an issue.

MY main question was if anyone else had this issue in the past and if so, what was the fix you found in case I missed something since these RVs tend to have oddities. Here is the water control valve to stop the flow through the heater core.

 

[THenne1713]

I was a mechanic for 25 years and have checked all the above you mentioned. The new elec valve works fine, I tested it prior to installation. The old one would not work when voltage applied through the control panel. The heat worked prior as the old guy had it bypassed with manual valve under the hood. My tests point to an air block possibly but I had a professional truck shop drop the antifreeze and redo it and still have an issue.

MY main question was if anyone else had this issue in the past and if so, what was the fix you found in case I missed something since these RVs tend to have oddities. Here is the water control valve to stop the flow through the heater core.

Had 74 Malibu V8 went to shop warranty x4 times first month for no heat on cold mornings in first 90 days. Same problem day after shop each time, all seemed good, so frustrated, I replaced heat valve annually for next seven years when heat would stop working but valve tested good. Failed every year religiously and new valve restored heat every time so blowing hot before we left the driveway. Still do not know why. But old vacuum operated valve always tested good and you could see it move.

 

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I have several manual valves under coach chassis from the engine cooling system. 2007 gulf stream tour master freightliner with 400 isl Cummins