Overpumping question

[judesudbury]

Hi folks,
With the central heating on and hot water off and the pump (50) on speed 3, the system pumps over into the header tank - it's a steady trickle, rather than anything more violent. If I turn the pump down to 2, the overpumping stops, but the two rads at the end of the circuit stay luke warm rather than hot. The bypass gate valve is shut, although there is a towel rad plumbed in like a big bypass circuit.

If anybody can offer any suggestion as to how I may prevent overpumping but still provide heat to all my rads, I'd be very grateful.

Cheers,
Jude

 

[YELLERBELLY]

Hey jude,sounds like the cold feed to your system is blocked,get it unblocked and it should be better

 

[judesudbury]

Hey jude,sounds like the cold feed to your system is blocked,get it unblocked and it should be better

Thanks dude - I've drained and refilled the system about 4 times in the last month (adding various radiators, doing repairs etc - just moved in) and the system fills up fairly quickly. If the CF was blocked - wouldn't I have noticed slow system filling time? Would even some restriction (scale deposits etc) to the CF cause pumping over?

I could remove a section of the CF pipework - up to near the pump perhaps and replace it. While I'm doing this - would raising the FE tank (and increasing the length of the CF and vent pipe help?

 

[Blooflame]

Or you could convert to a sealed system

 

[twgas]

Or you could convert to a sealed system

Do you know if OP's boiler is suitable for a sealed system?

 

[judesudbury]

Or you could convert to a sealed system

Do you know if OP's boiler is suitable for a sealed system?

Potterton Suprima 60, but I think I'll stick with the open vent system. I'm going to remove the air strainer (see my other post) and renew the cold feed pipe and tee and maybe raise the FE tank. Not sure about that last bit yet, my ceilings are over 2.5 meters high.

Cheers,
Jude

 

[seco services]

wheres the towel rail plumbed in ?

 

[judesudbury]

wheres the towel rail plumbed in ?

it's teed off just after the pump - it you look at the very bottom of the pic I posted on my 'what is this' question, you can just about see the towel rad tee.
Cheers
Jude

 

[seco services]

try putting your pump back on 2 and close the towel rail valve.
see if your 2 warm rads get hot.

 

[judesudbury]

try putting your pump back on 2 and close the towel rail valve.
see if your 2 warm rads get hot.

Actually, just turning the boiler stat down (it was on max) has stopped it pumping over, and the pump is still running on three.

Many thanks for your suggestions

Jude