currently have an ideal classic NF50 regular boiler (giant cold water tank and small tank in loft, plus hot water cylinder in airing cupboard on 1st floor). this boiler lives in a 3 bedroom detached house and i'm pretty sure it has been in since day zero. which makes it about 16-20 years old and possibly coming to the end of its lifespan.
since moving in, we've
1) converted the garage into a playroom/utility. this involved removing a 90cm width radiator in the hallway and replacing it with a bigger one that's about 1.5m in width just under the window sill in the conversion.
2) added a power shower (one of those with an integral pump - mira thermostatic event XS) into the family bathroom. the ensuite still has its old mixer shower with pathetic flow. not used much at mo but may consider getting pump on this one too in time to come when the kids are older? downstairs there's another communal toilet (just w/c and sink).
3) added a conservatory (no 'proper' rads in there tho! only an electric one). don't know if this is relevant!
in total - 9 proper radiators (including 2 towel rads which i like to keep red hot!) + power shower. there's quite a bit of hot water usage in this house (pots being done whilst someone having a shower). there's an immersion heater in the hot water cylinder but don't really use it that much cept in summer months. besides, the control panel allows me to turn on the hot water without having to switch on heating.
SO. last week or so i've gotten two quotes for a new boiler. because of the power shower, we're sticking to a regular boiler).
BG chap said to go with the worcester borsch greenstar 15ri. a quick google tells me my NF50 is 14.8 kW or thereabouts, so i guess it's a straight swap and pretty much logical seeing as the new boilers are meant to be more efficient.
local big-ish company guy comes round, thinks my boiler is 30kW for some reason (having not even looked properly on the control panel!), and recommends me a greenstar, but the 24Ri one!
so here's my question or ten
1) should i go for a happy medium of 18kW? 24kW seems to be a bit of an overkill as it's a whole 9kW above my current old boiler, which seems to be 'coping' at the moment anyway! after emailing him to say that my current boiler is 15kw and not 30kw like he thought, the local guy replies that 15kW would be slightly too little for our needs because of the 'extension' and the fact that we've got two little ones.
2) apart from the actual price of boiler (apparently differing by £100 or so, so not really a big deal as such), does it do any physical harm to the system if i get a over-sized boiler?
3) what about in terms of energy consumption (i.e. gas bills etc)? couldn't i just use the 24kW at a much lower setting or will that seriously set back the efficiency?
4) kinda irrelevant - is there any point in putting a TRV on a bathroom towel rad?!
whew. looking forward to a deluge of opinions!
since moving in, we've
1) converted the garage into a playroom/utility. this involved removing a 90cm width radiator in the hallway and replacing it with a bigger one that's about 1.5m in width just under the window sill in the conversion.
2) added a power shower (one of those with an integral pump - mira thermostatic event XS) into the family bathroom. the ensuite still has its old mixer shower with pathetic flow. not used much at mo but may consider getting pump on this one too in time to come when the kids are older? downstairs there's another communal toilet (just w/c and sink).
3) added a conservatory (no 'proper' rads in there tho! only an electric one). don't know if this is relevant!
in total - 9 proper radiators (including 2 towel rads which i like to keep red hot!) + power shower. there's quite a bit of hot water usage in this house (pots being done whilst someone having a shower). there's an immersion heater in the hot water cylinder but don't really use it that much cept in summer months. besides, the control panel allows me to turn on the hot water without having to switch on heating.
SO. last week or so i've gotten two quotes for a new boiler. because of the power shower, we're sticking to a regular boiler).
BG chap said to go with the worcester borsch greenstar 15ri. a quick google tells me my NF50 is 14.8 kW or thereabouts, so i guess it's a straight swap and pretty much logical seeing as the new boilers are meant to be more efficient.
local big-ish company guy comes round, thinks my boiler is 30kW for some reason (having not even looked properly on the control panel!), and recommends me a greenstar, but the 24Ri one!
so here's my question or ten
1) should i go for a happy medium of 18kW? 24kW seems to be a bit of an overkill as it's a whole 9kW above my current old boiler, which seems to be 'coping' at the moment anyway! after emailing him to say that my current boiler is 15kw and not 30kw like he thought, the local guy replies that 15kW would be slightly too little for our needs because of the 'extension' and the fact that we've got two little ones.
2) apart from the actual price of boiler (apparently differing by £100 or so, so not really a big deal as such), does it do any physical harm to the system if i get a over-sized boiler?
3) what about in terms of energy consumption (i.e. gas bills etc)? couldn't i just use the 24kW at a much lower setting or will that seriously set back the efficiency?
4) kinda irrelevant - is there any point in putting a TRV on a bathroom towel rad?!
whew. looking forward to a deluge of opinions!
