Hi, looking for some assistance with our heating system problems, i've done a few searches but not sure as the problems are quite strange.
System is 5 years old, Baxi Solo 3 boiler in kitchen, hot water tank in upstairs cupboard, feed tank in loft.
History of system...
New build house in 2005
Heat exchanger cracked in 2007 - while on holiday - fixed by 1st engineer in phone book (mistake)
6 months later heat exchanger failed again - replaced under warranty - think wasn't fitted properly.
2009 - three-way valve replaced (heating but no hot water)
Current problems -
During cold winter (-5 and more) noticed strip of ice running down wall outside from boiler vent. Approx 5 foot long and 3in wide/1in thick at top near vent. No other houses seemed to have this.
Heating would not heat house to anywhere near thermostat temp - getting up to about 19 deg C until boiler turned up to nearly max temp - then boiler started overheating.
One radiator not working - TRV looks OK - now two radiators not working - second one is the one with no TRV. Don't need bleeding, water comes out immediately - tried bleeding small (non-TRV) one - about 2 pints out of it, and radiator got almost luke warm.
When heating comes on it runs for about 30-40 mins then goes off for about 5 mins, then on for 5-10 mins, then off for 5 mins etc etc
After running for a couple of hours you can hear when it goes off a kind of "fizzing" noise from the boiler - bit like a kettle boiling with little water, and excessive steam from vent.
Feed tank in loft checked, water in it, ball-cock working fine.
Side note - heating pump runs 24/7 - always has from day 1
No problems with Hot Water.
Would love some ideas of what to check, had an engineer look at it, but it worked fine for him, need more info before getting him back.
TIA
System is 5 years old, Baxi Solo 3 boiler in kitchen, hot water tank in upstairs cupboard, feed tank in loft.
History of system...
New build house in 2005
Heat exchanger cracked in 2007 - while on holiday - fixed by 1st engineer in phone book (mistake)
6 months later heat exchanger failed again - replaced under warranty - think wasn't fitted properly.
2009 - three-way valve replaced (heating but no hot water)
Current problems -
During cold winter (-5 and more) noticed strip of ice running down wall outside from boiler vent. Approx 5 foot long and 3in wide/1in thick at top near vent. No other houses seemed to have this.
Heating would not heat house to anywhere near thermostat temp - getting up to about 19 deg C until boiler turned up to nearly max temp - then boiler started overheating.
One radiator not working - TRV looks OK - now two radiators not working - second one is the one with no TRV. Don't need bleeding, water comes out immediately - tried bleeding small (non-TRV) one - about 2 pints out of it, and radiator got almost luke warm.
When heating comes on it runs for about 30-40 mins then goes off for about 5 mins, then on for 5-10 mins, then off for 5 mins etc etc
After running for a couple of hours you can hear when it goes off a kind of "fizzing" noise from the boiler - bit like a kettle boiling with little water, and excessive steam from vent.
Feed tank in loft checked, water in it, ball-cock working fine.
Side note - heating pump runs 24/7 - always has from day 1
No problems with Hot Water.
Would love some ideas of what to check, had an engineer look at it, but it worked fine for him, need more info before getting him back.
TIA