Why would my boiler do this?

[okgo]

Hi all,

Recently moved into a place, it had a brand new Worcester boiler installed a week prior to moving in.

It has been fine in terms of producing hot water on demand (there is no tank here) however when the heating is put on, it fires up for about 20 minutes then stops, even though the room temp is nowhere near what I want it to be. For reference I want the place at about 21/22 deg, and I don't think its getting above about 18 before i just cuts out...

The pressure is at about 1 bar if that makes any difference.

Thanks for any help you can give

[philh]

Boilers have an inbuilt thermo stat to stop them overheating, i presume this is kicking in and stopping the boiler till it cools down enough, is the pump running?

[okgo]

Ok fair enough, but how is m flat ever going to get warm enough it keeps doing this? And what is a modern boiler doing if it has to cut out after 20 mins? Surely they are designed to stay on longer than that?!

Which pump?

Where will it be? And what do I need to listen for?

[mk1fan]

Sounds like it's not been set up correctly. The installer needs to come back and do this.

[louiebaby]

philh said:

Boilers have an inbuilt thermo stat to stop them overheating, i presume this is kicking in and stopping the boiler till it cools down enough, is the pump running?

Mine trips out when it overpressurises.

The trick is to run it at lower temp for longer...

[Gingerbread Man]

Is the boiler stat turned up?

[Gingerbread Man]

Is the boiler stat turned up?

[Deva Link]

okgo said:

For reference I want the place at about 21/22 deg, and I don't think its getting above about 18 before i just cuts out...

How are you measuring and controlling the temp?

These boilers normally have a programmable thermostat. Set for 22C (or whatever) and it should run until it hits that - it may cycle on and off as it approaches the set temp.

The boiler thermostat (for heating) should be on max.

Having said that, my daughter's place has a Worcester combi boiler and her house struggles to get warm. I think it's poor (40 year old) radiator pipework siz e and layout so the system can't carry enough heat, plus I suspect her boiler isn't modulating it's burner power properly, so it shuts off. Once it's shut off, there's a timer that keeps it off for 3 mins. Doesn'r seem long, but in very cold weather that drops the whole system water temp a lot.

[okgo]

The boiler has settings 1-5 I had it on 5 before and it seemed to stop even quicker. Its on 3 now.

Should I turn it up full then?

[cjs]

Have you got a room thermostat? Have you got TRV on your rads?

[andy43]

mk1fan said:

Sounds like it's not been set up correctly. The installer needs to come back and do this.

That.

[Gingerbread Man]

louiebaby said:

philh said:

Boilers have an inbuilt thermo stat to stop them overheating, i presume this is kicking in and stopping the boiler till it cools down enough, is the pump running?

Mine trips out when it overpressurises.

The trick is to run it at lower temp for longer...

Then you just have the boiler coming on and off for longer and waste gas.

[Ferg]

It sounds like either the boiler thermostat isn't set high enough (but it appears it is), the system is circulating badly...sludge, air, and the boiler temperature is rocketing OR there's a bypass/open radiator close to the boiler which is short circuiting the system. Is the pump/pump monobloc vented properly?

[Gingerbread Man]

okgo said:

The boiler has settings 1-5 I had it on 5 before and it seemed to stop even quicker. Its on 3 now.

Should I turn it up full then?

The boiler stat should always be on full. If you've a room stat fitted, it should be this that dictates whether the boiler comes on for heat and then off when satisfied. If the boiler is cutting off before the stat it could well be the boiler stat interfering. I'm ashuming it doesn't overheat?

I'd say to get the plumber back in who fitted it. But it might be a boiler fault and not in the install.