Gloworm condensing bolier

[cs119]

I've had british gas to service my bolier in the last few weeks due to the overheat button poping out on the bottom of the boiler, it's poping out every 30mins approxamately, also I getting hot water in the expansion tank in the loft, they have changed out the thermostat out and put fastcleanse in the system. British gas are telling me that there is a blocked cold feed from the expansion tank, and a powerflush is needed, however the pipework in the loft is not that old say 3-4 years.
I've bleed the system there is no air in the rads or pipwork in the loft

Has anyone got any idea what my problem is ???[/b]

 

[keego]

Turn off the supply to the F&E tank & drain a bit of water from a drain off or rad. If the water level in the tank drops then your cold feed is fine.
What type of system have you got, does it have one valve with 3 pipes from it (3 port) or 2 2 port valves.
Part of your problem is BG.

 

[simond]

The pipework blockage BG are alluding to (if their diagnosis is correct) will be in the airing cupboard and not in the loft.

Why is the pipework in the loft new? It is unusual to replace loft pipework unless there is a reason, so I'm curious.

 

[bengasman]

What temperature are flow/return?
Do you have the boiler control on max?

 

[cs119]

Thats a thought, I will try draining a bit of water off fom the F & E tank. The system is an s plan system 2 2port valves. Glo Worm Energy Saver 60e boiler.

The loft pipework was replaced when we fitted a new hot water tank, just whilst we were at it.

BG drained off part of the system last week and added Fast Cleanse.

Yes the boiler is on maximum. BG turned it down which made the matter worse so I turned it back up and the boiler stays on a short while longer.

Before the problem started, the boiler used to turn itself on and off quite frequently to keep it's temperature, however, now it stays on permanently until the overheat button pops out and there is a noise in the loft like a train rushing past(!), then the hot water goes into the header tank.

The flow and return are the correct temp, one hot and one cold.

 

[bengasman]

sounds like the boiler control is not working; your boiler should not be running on max, return temp should be below 55C

 

[Deleted member 105431]

to ublock your cold feed is a 30 minute job costing under a fiver in materials, don't fall for the Bg sales bullshit. Bung the tank, cut approx 6 inches up from the tee and rod it out with a screwdriver/brush, rejoin using a compression socket. Easy! How much for a ****ish gas power rinse/flush? THEY ARE CONMEN.

 

[gas4you]

Without agreeing to the politics of DM's post, the practicality's of his post are sound