overheat switch trips

[mcelroy]

Glow worm spacesaver boiler overheat trips after about an hour. Hot water from (think its vent pipe) flowing into header tank in loft. Is this normal? Radiators never feel as hot as I think they should. Any ideas. Have I a blockage somewhere and do I need a power flush. Any ideas on price if this is required. Thank You

 

[pav]

No you do not have a blockage and a power flush would be a waste of time and money in this case. Almost certain the pump is not working to it's full capacity. I would have this checked out before doing anything. If problems persist then post back

 

[plumberoy01]

hi mate dont know if you have sorted problem but when mine done that it was the thermostatic control knob on the boiler up the creak

 

[ChrisNut]

Glow worm spacesaver boiler overheat trips after about an hour. Hot water from (think its vent pipe) flowing into header tank in loft. Is this normal? Radiators never feel as hot as I think they should. Any ideas. Have I a blockage somewhere and do I need a power flush. Any ideas on price if this is required. Thank You

Sounds exactly like the problem I have.

I have a Glowworm "Ultimate fanned flue range", I believe it's
the '100-120FF' according to my useage instructions.

Problem is the same as mcelroy's..
I hear a boiling type sound in the loft directly above the airing
cupboard where the hot water storage tank is. Sounds like the
storage tank in the loft is boiling or something. Then the boiler
overheat clicks and shuts the system down.

Radiators are hot, but again, as mcelroy says, they don't feel
as hot as they should be. They are bled fairly regularly too.

I did open the bleed valve (I think it was) on the pump, but i'm
not sure if it's working ok. Any way to test this? It does seem
to be making the usual pump sounds and i can feel it working,
but it's very very hot to the touch when it's on - not sure if that's usual?

plumberoy01:
Is there any way to tell if it is the thermostatic control knob on
the boiler without replacing it ?

Thanks all.

 

[ChrisNut]

*bump*

 

[Nige F]

Glow worm spacesaver boiler overheat trips after about an hour. Hot water from (think its vent pipe) flowing into header tank in loft. Is this normal? No...........British Gas would love to give you a powerflush @£400 or so.it`s their answer to everything (allegedly)

 

[Roddders]

I came across similar on two installations.

1) The pump was on its way out and actually you could smell a burning smell.

2) Other occasion the pump was working at it's limit, Really only upstairs rads were getting piping hot others further on on thesystem were luke warm or cold. I therefore replaced pump for the more powerful of the 2 domestic Grunfos pumps and didn't have any further problems.