Worcester Bosch Greenstar 28CDi? Heating great, DHW hot water totally freezing even though boiler responding to demand
Boiler worked perfectly, both heating and hotwater, till Saturday when had to refill due to:-
I bumped a poorly mounted Radiator, it fell of the wall, joints gave way, place flooded,
-5 degrees up here so ice everywhere, everyone including baby got ill within 24hours, domestic misery.
However on the upside:-
Fixed the rad and the joints.
With the boiler off, ran cold water through the heating system to give it a quick flush. Repressured the system, bled the rads, all good. Fired up the boiler heard it auto vent. All good, heating back on no issues , heating just working like a dream
BUT
Domestic Hot Water (which always worked perfectly till the day of the "incident") is now totally cold, and I mean totally freezing.
Now when running hot water (regardless of heating on or off) Boiler does as it should firing up, fan going etc but cuts out after several minutes. Most surprisingly the Domestic Hot Water out flow even right at the boiler is always now freezing cold not even the tiniest lift in temp.
I'm guessing the overheat kicking in because the heat is never getting exchanged to the DHW circuit. However I can't understand it can be, there is not even the tiniest lift in the temp at the DHW outflow pipe, its like the cold water is not passing into the already toasting hot boiler at all. Is this possible the cold water can totally miss the w2w heat exchanger? Or can these boilers end up with a giant airlock in the primary side of the water to water exchanger? I didn't do anything to actively vent the boiler after refill, is there a procedure?.
Obviously kean to avoid the hot water taps merely becoming ice cube dispensors for yer Christmas Drink.
My understanding is based on my 13 year friendship with an old Worcester240 so correct me if I've misunderstood how this WB greenstar one works.
Help very much appreciated.
Boiler worked perfectly, both heating and hotwater, till Saturday when had to refill due to:-
I bumped a poorly mounted Radiator, it fell of the wall, joints gave way, place flooded,
-5 degrees up here so ice everywhere, everyone including baby got ill within 24hours, domestic misery.
However on the upside:-
Fixed the rad and the joints.
With the boiler off, ran cold water through the heating system to give it a quick flush. Repressured the system, bled the rads, all good. Fired up the boiler heard it auto vent. All good, heating back on no issues , heating just working like a dream
BUT
Domestic Hot Water (which always worked perfectly till the day of the "incident") is now totally cold, and I mean totally freezing.
Now when running hot water (regardless of heating on or off) Boiler does as it should firing up, fan going etc but cuts out after several minutes. Most surprisingly the Domestic Hot Water out flow even right at the boiler is always now freezing cold not even the tiniest lift in temp.
I'm guessing the overheat kicking in because the heat is never getting exchanged to the DHW circuit. However I can't understand it can be, there is not even the tiniest lift in the temp at the DHW outflow pipe, its like the cold water is not passing into the already toasting hot boiler at all. Is this possible the cold water can totally miss the w2w heat exchanger? Or can these boilers end up with a giant airlock in the primary side of the water to water exchanger? I didn't do anything to actively vent the boiler after refill, is there a procedure?.
Obviously kean to avoid the hot water taps merely becoming ice cube dispensors for yer Christmas Drink.
My understanding is based on my 13 year friendship with an old Worcester240 so correct me if I've misunderstood how this WB greenstar one works.
Help very much appreciated.
