Community Forums

DKW · 03-06-2017, 04:47 PM

After researching several RV blogs and confirming that I have hot coolant from the engine, I find the two vacuum valves that control the water circulation from the engine. With the engine warmed up and the dash controls set to high heat or defrost mode (blowing cool air) one valve is open and one is closed. There are two hoses coming in and two hoses coming out. Is it normal for one valve to be closed for heat mode? I would expect both valves to be open to circulate the hot water. I have attached a photo of one valve. Thanks for any help. David

2002 CC Intrigue
400 ISL
Peoria, Az

Murf2u · 03-06-2017, 07:53 PM

That looks like a standard by-pass valve, the offset in the lines allows the (in the picture) horizontal portion to move back & forth to send coolant right back to the engine in the summer time to keep heat load in the coach down.

If you have a leak in a vacuum line, or bad electric vacuum pump if so equipped, you won't be pulling enough vacuum to move the valve. Or it's just sticky from not being moved enough.

TR4 · 03-06-2017, 08:28 PM

David,

My Intrigue also has two valves, one for drivers side and one for passenger side. Make sure both sides are set to high for heat. Then both valves should be open. You should hear the vacuum pump running when you first turn the key on. Mine stops after about ten seconds. If it keeps running you have a vacuum leak. My coach also has a circulation pump at the rear next to the transmission (school bus pump). It helps get the hot water up to the front. Many people bypass these do to failure. The pump helps with heat, but isnt needed.

As Murf2u stated, the valve might be stuck. Just move it back and forth and it might work again.

Bill

dons2346 · 03-06-2017, 09:25 PM

Quote:

Originally Posted by TR4

David,

My Intrigue also has two valves, one for drivers side and one for passenger side. Make sure both sides are set to high for heat. Then both valves should be open. You should hear the vacuum pump running when you first turn the key on. Mine stops after about ten seconds. If it keeps running you have a vacuum leak. My coach also has a circulation pump at the rear next to the transmission (school bus pump). It helps get the hot water up to the front. Many people bypass these do to failure. The pump helps with heat, but isnt needed.

As Murf2u stated, the valve might be stuck. Just move it back and forth and it might work again.

Bill

Yup. Having the pax switch set to supply heat is a big issue. The pump TR4 mentioned is on the driver's side on the frame rail.