Vauxhall Owners Network Forum banner
1 - 10 of 10 Posts

·
Registered
Joined
·
231 Posts
Discussion Starter · #1 ·
The heater is blowing luke warm to cold air, I have tried resetting several times, I have also got a new heater bypass valve on. After running today the heater pipes are only luke warm.

How does the heater bypass vacuum work? the system is not opening the valve so is there a way of checking? Where is the initial vacuum supply drawn from so I can start to check pipes etc?
I bought the car with a blown head gasket & since I have completed it the heater has never been hot so I am wondering if I have put a vascuum pipe on wrong somewhere?
 

·
Registered
Joined
·
231 Posts
Discussion Starter · #3 ·
Thermostat is new, engine is running fine at the correct temp, just the heater pipes are not heating, heater has been flushed so the valve seems not to be opening.
 

·
Registered
Joined
·
231 Posts
Discussion Starter · #5 ·
That was what I was thinking but water seems to flush through ok. Would a seperate vacuum supply to open the HBV work? If I could open it fully I would know if there was a circulation, I presume a vacuum opens the valve?
 

·
Registered
Joined
·
231 Posts
Discussion Starter · #7 ·
There is a vac pipe which goes from the HBV to the bulk head, I disconnected this and tried it on my old valve which still works. There is no vacuum whether the heater is on or off.

2 questions,
Does a vacuum open this valve or close it?
Where is the vacuum supply picked up from?
I will have to have the scuttle off for a better look later in the week.
 

·
Registered
Joined
·
237 Posts
There is a vac pipe which goes from the HBV to the bulk head, I disconnected this and tried it on my old valve which still works. There is no vacuum whether the heater is on or off.

2 questions,
Does a vacuum open this valve or close it?
Where is the vacuum supply picked up from?
I will have to have the scuttle off for a better look later in the week.
I believe no vacuum means hot water flow to heater and vacuum means no water flow to heater. Don't know the answer to question 2, but its irrelavent as you do not need vacuum for heat.
Is the bypass valve connected correctly.
Alan
 

·
Registered
Joined
·
231 Posts
Discussion Starter · #9 ·
Cheers, I was wondering the same. I will be checking it out now I am on rest days. I will let you know.
 

·
Registered
Joined
·
231 Posts
Discussion Starter · #10 ·
Just to share my solution as I have now got heat.
I checked the pipe work which was as it should be with no vacuum to heat. I flushed water through the matrix, still no hot water flow. I removed what I thought was the return [ the pipe with a Tee off ] and I had a flow through the matrix. I then put a hose to the return & flushed through to the expansion tank allowing it to overflow. I reconnected the heater pipe & the heater pipes started to get hot. It seems I either had an air lock or blockage on the return to or through the engine.
 
1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top