Ideal Boiler won't fire up?! Pls Help!

[Dando]

The pilot light is on, the pressure is just over 1 bar but when i turn on the heating or hot water the boiler doesnt fire up. The temp guage is quite low though, its showing 25 degrees celcius. The model is Ideal Sprint RS.75. This morning I did have to put pressure up a bit cos the pilot light was not staying on for long. I did this and everything was fine until I bled a rad cos the pressure was getting too high. Is it not firing now cos I havnt replaced the water I took out from the rad? How do I fill it?
Please help!!! Getting colder by the minute!!! [/b]

 

[meldrew's_mate]

Sounds like you know how to fill it 'cos you "put the pressure up".

It also sounds like the expansion vessel in the boiler has a fault. There's a schraeder valve on it, attach a car tyre gauge and read the pressure, if water spills out it's knackered, if it's less than 1 bar pump it up with air to 1.5 bar with the PRV open and the boiler off. Then close the PRV and "put the pressure up" to 1.5 bar, and turn on the system. If it goes over 2.5 bar when hot you have other problems.

See how you go....PJ

 

[Dando]

Hi, thanks for the reply. I can turn the pressure up (fill it) but wont it just keep going up to an unsafe 6 bar? When I do attempt to fill it I turn both white knobs on the underside, labelled filling valve, both at the same time. I'll try and give what you said a go though.

 

[Dando]

Can I take the DHW expansion vessels nut off? (the bit where you insert the car tyre pump guage). Is it safe to do so? I have disconnected from the mains.

 

[Dando]

PS What is PRV?