Rad Header Tank Overflowing

[skippyuk]

What i think is the Radiator overflow is doing its job right by returning the excess water to the radiator header tank (water in header tank is warm can see steam coming from it).
With the water being returned the header tank now contains too much water and is now coming out of the overflow pipe onto the drive. This has only been doing this since i changed the length of time the heating is on.

What can i do to return the heating system back to the way it was and stop the overflow?

PS: - It is defiantly not the ball cock valve leaking or not shutting off properly the water is coming from the return pipe.

Thank for your help

 

[chrishutt]

I think you'll find this sort of situation is discussed in the FAQ - Plumbing Tips topic. You probably have blocked pipework, maybe cold feed pipe.

 

[Meldrew's mate]

...and maybe a hole in the hot water cylinder's heating coil, as it's not normal for "pumping over", the symptom you describe, to cause the header tank to overflow.

Try tying up the ballcock, or better still turn off the mains supply to it, then see if it still overflows. Remember, water expands when hot (hence the name for the tank) so a warm system will cause the tank level to rise anyway.

You still have pumping over issues, re the sauna in the loft.

 

[chrishutt]

it's not normal for "pumping over", the symptom you describe, to cause the header tank to overflow.

Hi Meldrew's mate, nice to have you back on board.

But your statement above isn't true if the cold feed is blocked, is it?

 

[skippyuk]

Thanks for your replies to this

Chrishutt i have done what you suggested and looked in the FAQ and i only found this to relate to my problem

"Feed and Expansion tank

Open vented systems are filled and vented to a Feed & Expansion (F&E) tank. This is usually a small plastic tank in the roof space which is fitted with a float valve to fill automatically from the mains supply. The outlet pipe is the F&E pipe and the vent pipe inverts (upside down U shape) over this tank."

 

[chrishutt]

My apologies skippyuk. It's something that ought to be covered in FAQs since it's quite a common problem. It's certainly been covered before so perhaps if you do a search on blocked feed pipe you might find the other threads.

 

[lagunaglen]

On a safety note,if the header tank is plastic and the older type then it may start to bow out and in extreme circumstances can collapse , make sure its well supported on the base it sits on .

 

[JohnD]

Tie up the ball valve in the F&E and also in the cold tank that feeds the hot water cylinder. Mark the water levels in both. Sit up there with your torch for half an hour with the heating running but no-one running any taps.

Then look at the water levels and tell us what happens. I bet I know but it would be foolish to diagnose without some kind of experimental test.

p.s. chrishutt - surely if the F&E is blocked... it might come up the vent as it gets hot... but if it's running out of the overflow, and not being topped up through the blocked feed pipe, it won't do that for long.

 

[chrishutt]

p.s. chrishutt - surely if the F&E is blocked... it might come up the vent as it gets hot... but if it's running out of the overflow, and not being topped up through the blocked feed pipe, it won't do that for long.

What if the feed &expansion pipe is just partially blocked? The water pumping over will not be able to return to the circuit fast enough and will eventually overflow, but the water in the F&E tank will slowly find it's way back into the system and when the pump is off any net loss will be replenished by the float valve. I'm not saying that's necessarily happening here, but it's a possibility.

 

[bengasman]

Depending on how much water flows out and how often, but if considerable you floatvalve would seem to let by.

 

[JohnD]

I'm with Meldrew's mate and awaiting results.