Hi there, I have a Worcester Bosch Greenstar 42CDi natural gas combi boiler that was installed 5 years ago and has always perfectly. However yesterday morning we noticed it wasn't heating the hot tap water. It's also worth noting that we've only just this week turned the heating on after the summer.
On closer inspection it appears that the boiler does heat (water and radiators) until the temp gets to 109 degrees (i.e. U09 on the display) and you can't get the boiler to fire up again. If we reset it, when the water's cooled down it starts heating for a bit whilst also running the siphon-fill programme (I've looked up the -II- symbol shown on the display in the manual and this is what it means). Apparently this is OK and doesn't mean a fault, unless it keeps doing it, which is the case for us, so there presumably is a problem. This cycle keeps happening and means we've got hot water in the taps and rads for a bit before it suddenly shuts off again.
After bleeding the rads (only one had any air in it) I also tried to repressurise the boiler (it's currently at 1.0bar) as I've done two or three times before with no problem but I can't get any water to come in - no rush of water sound and pressure rising as you normally get. I suspect this may be related to the problem above and reading around on various forums this may mean the filling loop is seized and needs replacing (?).
Any pointers/advice would be gladly received as I have two young kids. I presume I'll need to get a heating engineer out (but would prefer not to) but having a solution before I do call one will save hassle/money hopefully.
Cheers,
Jamie
On closer inspection it appears that the boiler does heat (water and radiators) until the temp gets to 109 degrees (i.e. U09 on the display) and you can't get the boiler to fire up again. If we reset it, when the water's cooled down it starts heating for a bit whilst also running the siphon-fill programme (I've looked up the -II- symbol shown on the display in the manual and this is what it means). Apparently this is OK and doesn't mean a fault, unless it keeps doing it, which is the case for us, so there presumably is a problem. This cycle keeps happening and means we've got hot water in the taps and rads for a bit before it suddenly shuts off again.
After bleeding the rads (only one had any air in it) I also tried to repressurise the boiler (it's currently at 1.0bar) as I've done two or three times before with no problem but I can't get any water to come in - no rush of water sound and pressure rising as you normally get. I suspect this may be related to the problem above and reading around on various forums this may mean the filling loop is seized and needs replacing (?).
Any pointers/advice would be gladly received as I have two young kids. I presume I'll need to get a heating engineer out (but would prefer not to) but having a solution before I do call one will save hassle/money hopefully.
Cheers,
Jamie
