Worcester boiler pressure question

[debj]

Hello

I have a worcester greenstar 28i junior with (I think) a bit of a pressure issue. When the system's cold, it sits at 1 bar, but when the heating is on, even for a short time, the pressure goes all the way up to 3 bar into the red. The system isn't dumping water out as the outlet pipe outside is bone dry, and it's not falling below 1 bar when cold, so I've not had to top anything up and I don't want to bleed the radiator as the pressure will then be too low when cold.
We have an engineer coming out on Tues to have a look at it - my question is, is it ok to use the boiler for the heating in the meantime? The pressure doesn't rise much at all when the hot water is running, only when the heating is on, so we could manage without heat if we have to for a bit as long as we've got hot water. I don't want to damage the boiler or have anything go 'bang' if the pressure is too high.
Thanks

 

[ShaunCorbs]

Yes fine to use nice easy issue that any good heating engy should solve

Just keep an eye on the pressure (make sure there's always about 1 bar on the gauge)

 

[Harvest Fields]

Any good heating engineer.

 

[townfanjon]

It will probably still work under 1 bar ( cold ) , try not use the heating at all and you will probably get through until Tuesday

 

[debj]

Thanks for the replies Much appreciated.
It's been like this for about a week now and I adjusted the temp on the thermostat so it won't be on for as long in the mornings, and the warm weather means the heating's not on that much.
The heating has been on this evening (on constant, but coming on and off to keep up to temp) and the pressure's been about 2 - 2/12 bar so not too bad.
Weirdly, when the hot water is running, the pressure drops slightly (about 1/4 bar) and then goes back up when you turn the hot tap off. Is that usual for combi boilers or related to the other pressure issue?

 

[lame plumber]

Thanks for the replies Much appreciated.
It's been like this for about a week now and I adjusted the temp on the thermostat so it won't be on for as long in the mornings, and the warm weather means the heating's not on that much.
The heating has been on this evening (on constant, but coming on and off to keep up to temp) and the pressure's been about 2 - 2/12 bar so not too bad.
Weirdly, when the hot water is running, the pressure drops slightly (about 1/4 bar) and then goes back up when you turn the hot tap off. Is that usual for combi boilers or related to the other pressure issue?

totally understandable for a combi, if you really want an answer as to why someone can explain it, but basically it is fine for now. if it loses all pressure just top it up and dont use central heating but only HW

 

[kris]

Hi there debj and welcome to the forum,,,, Yeh youve a pressure problem which will require the attention of an engineer, there is a safety mechanism inside the boiler that when the pressure rises too high (3bar) it will automatically dump water out of the pipe outside ,

 

[Harvest Fields]

It sounds like it has not got to that stage yet. Hopefully it lasts until her engineer is attending on Tuesday.

 

[Dan]

I'll close this thread.

Unfortunately there's not much we can do you'll just have to wait for your heating engineer. If things get worse try to find somebody that can come quicker perhaps.

We have a jobs area on the forum you could post in but given the time of year i doubt you'd get somebody any quicker i must be honest.