Glow worm 30si

[thecoop]

British Gas, Heatcall and now my original installer can't figure out this problem - PLEASE SOMEONE HELP!!

Rads downstairs started to go cold, upstairs hot. Turned off upstairs rads and downstairs fine. Rads balanced - still same problem. Pump changed - still same problem. Now boiler coming on intermittently by saying it gets to temp then cutting out.

System has been flushed etc.

I have asked for termo valves to be removed as my last hope.

Could this be the ultimate problem or any other ideas. Seems this site is the only one with decent answers!

Thanks.

 

[croydoncorgi]

Where's the boiler installed?
What's the pipe layout? (eg. downstairs rads supplied by pipes from upstairs? from under ground floor?)

 

[doitall]

How to design a heating system ??

If the upstairs or downstairs gets hot but not at the time, then you have a circulation problem, thermostatic valves would improve the situation by sending water to other rads as it reached temp.

Can I assume it never worked or is this something that came on recently

Pipe sizes, age as well as boiler and pump details would be handy.
Did the not so experts have any suggestions, like pump undersized, pipes undersized 8mm, 10mm, did they check any Motorised valves that may be broken, a by-pass valve thats not set up, and reducing the system head.

 

[thecoop]

Many thanks for the info. All really useful and will hopefully lead to solution!

As an update the system is 18 months old. Worked okay until last few months although never thought rads were hot enough and put this down to thermo valves.

Pipework standard - 1mm I beleive. Boiler located in kitchen.

I have been told pump standard size for boiler, told me a valvue should have been installed by tank (plumber now done).

Now shower has stopped working due to water pressure too low and bolier now not keeping a consistent temp. Keeps cutting out when it reaches max. 73 degrees.

Any advice would be appreciated.

 

[ChrisR]

Please let us decide whether pipe sizes are standard!
As CroydonCorgi and Doitall have asked,
(1 mm is a bit small for the pipes. )
What size comes off the boiler and what size are they to the rads. Do you have a solid floor downstairs which means the pipes come down to each rad from one above?

How big is the house(no of bedrooms will do)? What is written on the pump please - may be something like 15-50 or 15-60 or 5m or 6m.

You have stated "rads balanced" - but they can't be or you wouldn't have a problem

 

[thecoop]

Many thanks for all your help.

After having the pump changed, thermo valves changed, room stat added it appears that the GlowWorm 30Si has a possible design fault.

All the dirt, bits of old pipework etc. had been flushed through to a spring valve that has no use on this boiler. Although it is set in the open position it allows all this rubbish to collect and cause the problems I have had!!

Has anyone else ever seen this?

 

[boilingover]

Dear Thecoop,

please help!! I have just found your posts and I have a glow worm 30si that has exactly the same symptoms as yours had. My plumber has replaced pump, flushed etc.
Do you know where the spring valve is located? or if not, who told you bout it and what their contact details are?

many thanks