we are having a single storey extension built in place of an old conservatory. It used to have 2 big double radiators but all the heat was lost through the roof so was freezing in winter. There was no door between kitchen and conny so that was always freezing too so we decided to bite the bullet and get rid of it ! The extension will have underfloor heating about 22m sq m plus about 10 going in the current kitchen that will be turned into utility room.
we have gravity fed/vented central heating and hot water tank. The boiler was replaced last year with a 'Worcester CDI 30 regular' when we moved in because the old one was knackered. We didnt know at that time (was summer) that we would end up getting rid of the conservtory so didnt oversize the boiler with any extra capacity in mind.
The plumber (part of the building firm) suggests that the existing boiler is not powerful enough for the extra heating needed. he says we need 120000 BTU based on number radiators + UF heating and size of HW tank but the worcester is 105000. he also suggested to take out the old gravity fed setup and go to sealed system heating and megaflo as its better in the long run for the size of house (4 bed detached, 2 adults + 2 kids).
Obviously Im a bit reluctant to take out a 6 month old boiler for one with a bit more oomph as its a big waste of money if not needed. Im also concerned we dont have sufficient pressure & flow rate for the megaflo - garden sprinker is rubbish in the summer heatwave. Plumber said could be solved by an accumulator. Currently the HW tank (open vent, 180 litre) is boosted by pumps for the showers & bath at that seems fine (but pumps cheap, old & noisy so can get new ones).
other posts suggest the requirements of a boiler is more determined by its ability to heat hot water than it is by the central heating - if so, couldnt we just keep our 30 kw and the same HW tank and assume its also powerful enough for the extra central heating ? can UF heating be run by a gravity fed/open setup or does it need sealed system ? maybe we just install the UF heating and see how it goes through the winter and if the heating and or HW struggles then we upgrade the boiler ? can the central heating be sealed system but the HW remain gravity fed/open ?
any thoughts please as I dont want to spend money unnecessarily (who does!)
thanks,
Nick
we have gravity fed/vented central heating and hot water tank. The boiler was replaced last year with a 'Worcester CDI 30 regular' when we moved in because the old one was knackered. We didnt know at that time (was summer) that we would end up getting rid of the conservtory so didnt oversize the boiler with any extra capacity in mind.
The plumber (part of the building firm) suggests that the existing boiler is not powerful enough for the extra heating needed. he says we need 120000 BTU based on number radiators + UF heating and size of HW tank but the worcester is 105000. he also suggested to take out the old gravity fed setup and go to sealed system heating and megaflo as its better in the long run for the size of house (4 bed detached, 2 adults + 2 kids).
Obviously Im a bit reluctant to take out a 6 month old boiler for one with a bit more oomph as its a big waste of money if not needed. Im also concerned we dont have sufficient pressure & flow rate for the megaflo - garden sprinker is rubbish in the summer heatwave. Plumber said could be solved by an accumulator. Currently the HW tank (open vent, 180 litre) is boosted by pumps for the showers & bath at that seems fine (but pumps cheap, old & noisy so can get new ones).
other posts suggest the requirements of a boiler is more determined by its ability to heat hot water than it is by the central heating - if so, couldnt we just keep our 30 kw and the same HW tank and assume its also powerful enough for the extra central heating ? can UF heating be run by a gravity fed/open setup or does it need sealed system ? maybe we just install the UF heating and see how it goes through the winter and if the heating and or HW struggles then we upgrade the boiler ? can the central heating be sealed system but the HW remain gravity fed/open ?
any thoughts please as I dont want to spend money unnecessarily (who does!)
thanks,
Nick