Ideal Mini C24 cold inlet problem / low pressure

23 Jul 2008
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United Kingdom
I have a 2 year old Ideal Mini C24, just out of warranty.

The water pressure is at 0 bar and subsequently the boiler is firing but cuts out after a short period of time.

I have located the cold water inlet, which appears to have been installed with a 'blue' valve below the boiler unit, however when i open the valve the pressure does not increase? and i cannot hear any water flowing into the boiler either? the water supply is okay in the rest of my property? the valve is quite stiff to operate and i am turning it clockwise to open it.

I am not sure why the systems pressure is not increasing? and or water is not feeding into the boiler.

Any ideas/solutions would be appreciated.


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Have you got the right tap ? If it shuts off the water going through the boiler it's the wrong one!

If not see the faqs - filling loop.
FIrst check for a tap at the other end of the flexy hose - may be screwdiver operated.
Is your blue tap actually turning anything?
Often the metal parts go stiff, so the plastic turns on the shaft. Remove plastic via small screw and use a small spanner.
Thanks ChrisR

Am pretty sure I have the right tap as the diagram in the service manual labels it 'DHW Cold Inlet'.

I will try your suggestions tonight and get back to you.

best regards

Sponsored Links don't. DHW cold inlet......Domestic Hot Water.....a clue in the has nothing to do with your Central Heating circuit. The blue tap is an isolator. Test it. Turn it off and open a hot water water...isolated.

To fill your central heating system you use a filling loop designed to connect mains cold water to the sealed heating system. This will be by an external filling loop between cold mains and heating pipe or an integral system used on some boilers. Get your manual out and read how it's done or send a pic
apologies, I assumed the 'cold inlet' was used to top up the system, my mistake.

I have now identified the actual filling loop diagram, and it is actually a flexible hose that connects to the 'CH return', the filling loop is isolated using a stop valve at either end with a double check valve assembly in between. I will loosen the screws on both stop valves and hopefully i will be able to increase the pressure to around 1 bar as recommended by the service manual.

Thanks again for your assistance and patience, I will keep you posted.

best regards

Thanks all, as I have managed to re-pressurise the system to 1 bar, hooray. The isolator valve was installed without a 'plastic lever', so i got a spanner to open it.

Now however, when the boiler fires initially (for either CH or DHW) it burns for around 5-10 seconds and then cuts out, i then need to reset (using the reset button) and then it seems to run okay. It seems to do this on the initial ignition only, after the boiler has been idle for a while? but then after a reset it runs okay? hmm?

I assume that you are pushing the red button in the middle which is the ignition failure reset.

It may just be an adjustment required or something more involved. However I cannot give you any detailed advice as that requires a competent CORGI engineer.


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