Anyone know anything about combi boilers?

[Jack]

We have a combi in the loft at home which was fitted feb last year by British Gas (previous owners removed night storage and had gas c/h fitted). We're having some issues with it now though - hot taps on their own are fine but if you also turn on cold, the hot tap pressure drops and the water goes stone cold. And the boiler makes some nasty sounding noises

I thought it might be pressure related, possibly the cold forcing its way back through the hot pipes somewhere so will check the gauge later tonight. Any other things i should check as well?

annoyingly and very unsurprisingly the BG 5yr warranty isn't worth the paper its written on as they say thats only valid with the people who lived here before

[philly]

We had a similair problem. Couldn't tell you exactly what it was. But something to do with a pcb board inside that they replaced. Probably no help but worth an investigate.

[leggattr]

Check the water pressure Guage. Believe it could be as simple as that. Needs to be around 2psi I think from last checking mine. I have a loop on mine so the system can be topped up if I bleed the rads etc and that raises the pressure.

[Andy]

1.6- NO more than 2bar
turbojolts ya man for this though

[turbojolt]

He really isn't

Does sound like a water supply issue anytime a boilers pressure runs low you get that grumbling noise! Is it shitting water out of the overflow?

[Jack]

Just had a quick look yesterday. Soooo if the pressure gauge reads 0 then I guess thats a bad thing?

[leggattr]

I've just read mine and I'm on 1 bar psi. I said max 2 bar but now believe it should be 1.5 really. I'm running an ideal logic combi. Sounds like you need to ad pressure to it. Must be a pipe linked to the system to do this?

[turbojolt]

Yer 0 isn't ideal

[Edd]

There should be a procedure for pressurising the system

Different models vary, Google your model, normally easy to do
Mines done by opening a valve with a flat blade screwdriver
Any fault codes on the display?

[mowgli]

Ok. There is always a pressure boost tap. But it sounds like your supply pressure is too low.