Help !!!! Combi problems

[Steve Pearsall]

hi everyone
I’ve just moved into a static caravan
We have Worcester Bosch Greenstar 30i on lpg
We only have one small radiator fitted to the bedroom. We get our heating from a wood burner. The boiler heats up then cuts out. Can I assume that the system doesn’t have enough radiator space to dump the heat from the hot water demand ?

 

[ianmcd]

you will probably find that the radiator is there to dump excess heat after running HW and was never intended to be turned on for CH

 

[Steve Pearsall]

But could the boiler cutting out be due to there not being enough system space to dump the heat. It’s a 400mm x 600mm single rad with 10 meters of 10ml copper pipe connected.

 

[ianmcd]

of course it will cut out, where is the heat supposed to go ?

 

[Steve Pearsall]

I’m greatly appreciative of your help Ian. So what’s the solution? More radiators ?
Or make a copper pipe heatsink and attach to the rad system ?

 

[bernardgreen]

where is the heat supposed to go ?

into the DHW would be the best place for all the heat. How much heat is dumped when the DHW stops flowing ?

 

[ianmcd]

I’m greatly appreciative of your help Ian. So what’s the solution? More radiators ?
Or make a copper pipe heatsink and attach to the rad system ?

No , just dont use the boiler to heat the radiator, just use it for HW and when you stop running the HW draw off, the burner will shut down and the pump will keep running and dump the heat into the radiator, a badly designed way of doing it but it should work, will never work on heating though, unless you fit a lot more radiators

 

[ianmcd]

into the DHW would be the best place for all the heat. How much heat is dumped when the DHW stops flowing ?

yet another thing that you have no clue about so back to Google

 

[bernardgreen]

yet another thing that you have no clue about

this dumping of heat every time hot water has been drawn is a clue as to why the real life "efficiency " of combi boilers in domestic hot water mode is far below the quoted figure.

 

[ianmcd]

Not what the OP is asking for advice on

 

[martyndc88]

The boiler temp shouldn't get so hot that it has to cut out at all when running hot water.

 

[Steve Pearsall]

I run it on LPG. I’ve just been informed if I have less than a quarter tank of gas it may not work properly. How true this is I don’t know
(I have to say that I’m not 100% sure it’s a thermal cut out that’s kicking in )

 

[martyndc88]

When you run the hot water what does the temp display on the boiler screen read?

 

[Steve Pearsall]

It doesn’t have a screen. Most of the time the boiler doesn’t even fire up. If I hit the reset button while the hot tap is running it fires for about 20 seconds then stops If I reset with no water flowing and then go to demand hot water it doesn’t even fire up Could the. Flow switch be buggered ?

 

[martyndc88]

Are you sure you've got a 30i? They have LCD screens.

If the boiler doesn't fire up at all when you run a hot tap then it does sound like