New combi boiler - pressure too high

moike

Bleeding the radiators is a very simple maintenance activity that is not going to do any harm, it's just that it won't solve this problem, The process described above is also very simple and is perfectly in the realms of user operation, you will need no tools.
The flexible pipe is intended only to be connected during the recharge operation, (although most people leave it connected) it will likely be the only 6" flexible pipe on your boiler and it will be such that you can remove it with your hands.
I suspect that the valves at both ends of this pipe are not fully turned off, and is why you are experiencing your pressure rising over time, you need to do this prior to disconnecting one end (which will also verify that both valves are off), once one end is disconnected, to reduce the pressure, open the boiler side valve and collect the excessive water in a bucket (via this pipe if possible)

geri1965_2

Hmmm - I understand what you are saying, I just can't relate to it in terms of my boiler. There is a flexible pipe but it doesn't look like it can be removed.

moike

Can you take a picture of it?
Is there a valve at both ends? these should both be off and would probably solve your rising pressure problem, although won't help lower the current pressure.

geri1965_2

Can't post a pic just now as my camera needs charging. I just called British Gas and they told me to turn the gas off and they will send an engineer tomorrow. Now I'm worried!

Canucklehead

Hi

British Gas 'service' consists of checking flue gas and visual inspection rather than doing things like checking the expansion vessel pressure. IMO this is your problem . The vessel has lost it's air charge and therefore will not accommodate the rise in system pressure when in use. The result is the 'mini explosion and discharge'

Other possibility is thermostat failure.
If you have never used the filling loop then I wouldn't expect it to be partly open.

Bleeding radiators will lower system pressure, and is not usually the answer to anything except when refilling a system.

Please let us know the outcome tomorrow.

Corgi Guy.

geri1965_2

Well, he suspects that the flexible hose is blocked and the flow switch is blown, so he needs to order some parts.

He said he could have checked the hose today but it would take a while and might leave us without hot water, which he doesn't want to do bearing in mind we are going away tomorrow, so he's going to fix it when we get back.

travel_freak

Hi,

Please excuse me butting in on this thread but I have a kind of related problem, albeit the other way around: the pressure in my boiler keeps dropping.

It stopped working completely recently, the pressure was too low. Re-filled the pressure to 1.5 but it has been dropping ever since then.

I understand that pressure drops can mean you have a leak somewhere but don't know where/how to troubleshoot where the leak might be. Please could anyone help with any suggestions for this?

Or, if it is not only related to a leak, what might the problem be?

Many thanks in advance.

By the way, the boiler is a Protherm, and is a combi.

Kind regards,

pwd

I have same problem - today.
Pressure is at 3 - max safe pressure.
The radiator nearest the boiler - has different valves then the other radiators - and for some odd reason hasnt come on this year(although havent touched the valves since last year). I tried bleeding it. got water out which lowered the pressure for a few moments.
I was wondering if the fact this radiator isnt coming on has any bearing on the pressure build up?
Do you have a radiator not coming on near boiler?