11 replies to this topic

[Robho]

I’ve just installed a new (T7) heater.

 

As background, I carefully clamped the heater hoses before disconnecting them and before reconnecting the them (and checking the clamps had no detrimental effect), I filled the new heater with coolant, in order to minimise air in the system. Then ran it up to temperature with the cap off the expansion tank.

 

With the engine and radiator hot (and the cooling fan cutting in), the heater hoses and tap remain cold (not even slightly warm). 

 

I checked with T7 in case there was something that I might have missed with the heater - seems not.

 

Prior to replacement, whilst the old heater was pretty ineffective the heater hoses would get hot to touch (a check I made just before deciding to order the replacement.

 

I can’t find anything that shows the coolant flow round the car. And searching on the forum only says there are no bleed points near the heater.

 

The heater hoses connect to two alloy pipes (which are not getting hot either) which disappear towards the rear of the car. How is the heater system fed – is it separate from the main cooling system?

 

Any guidance welcome to help diagnose this, thanks.

Rob

 

 

 

[hairy]

Hose arrangement is shown here: https://www.speedste...ings/index.html

[Ivor]

Sounds like an airlock

[Ivor]

Bit sure if there are bleed valves in the heater circuit

[Robho]

thanks for the detail. I don't believe there's a bleed in the heater circuit. I'm going to bypass the heater and tap to see what effect that has (to at least isolate it) ...

[Ivor]

thanks for the detail. I don't believe there's a bleed in the heater circuit. I'm going to bypass the heater and tap to see what effect that has (to at least isolate it) ...

Believe that there are bleed taps in the main cooling circuit

[ICD]

Go onto VX220 FaceBok and send Jim Dunk a message.

 

He isnt very far from you , and is an expert in T7 installation and would be able to help with diagnosis ...probably

[Bloke]

There is a bleed just by the passers headlight on the hose there.

Don't be surprised if you need a bit of a run and couple of heat cycles to finally sort it, when the stat first opens it will close and open a few times on the run before it stays open.

[Hammy of hamhouse]

Does indeed sound like an air lock .
If you can undo a hose somewhere on the heater circuit whilst it’s running and let some water out it might shift it.

Double check you have fitted the control valve correctly

Edited by Hammy of hamhouse, 09 January 2022 - 09:45 AM.

[Robho]

OK, thanks for the feedback.

 

The diagram from Hairy was a breakthrough since it (unlike the easier to find schematics) shows there IS a bleed valve in the heater circuit - its on an elbow a few inches from the expansion tank in the engine compartment. I had read a post saying there is not one by the heater - so this in part correct, since it is by the engine not the heater. (The bleed by the headlight is for the radiator circuit, not the heater, I believe)

 

Locating the correct bleed screw combined with a tip to rev the engine to force the coolant round the system solved the problem. 

 

cheers.

[Ivor]

OK, thanks for the feedback.

The diagram from Hairy was a breakthrough since it (unlike the easier to find schematics) shows there IS a bleed valve in the heater circuit - its on an elbow a few inches from the expansion tank in the engine compartment. I had read a post saying there is not one by the heater - so this in part correct, since it is by the engine not the heater. (The bleed by the headlight is for the radiator circuit, not the heater, I believe)

Locating the correct bleed screw combined with a tip to rev the engine to force the coolant round the system solved the problem.

cheers.

Result!

[Strugs]

 

OK, thanks for the feedback.

The diagram from Hairy was a breakthrough since it (unlike the easier to find schematics) shows there IS a bleed valve in the heater circuit - its on an elbow a few inches from the expansion tank in the engine compartment. I had read a post saying there is not one by the heater - so this in part correct, since it is by the engine not the heater. (The bleed by the headlight is for the radiator circuit, not the heater, I believe)

Locating the correct bleed screw combined with a tip to rev the engine to force the coolant round the system solved the problem.

cheers.

Result!

 

 

Long live .org!!