Hello all, I am looking to replace my 12 year old SIME Friendly combi boiler. I have had 3 quotes from local installers. The quotes all seem reasonable. I have a 3 storey mid-terrace property with 5 bedrooms, 1 shower room (Thermo mixer) and a bathroom. Altogether 11 rooms with rads plus hall and extension = 13rads. Fully DGlazed. 22mm supply pipe. I suggested after some research (WHICH) that a Worcester Bosch boiler would be a good choice. The quotes seem to favour the 29cdi model. The old boiler had a rating of 24kW. The main gripe with the SIME was the bath filling time and the noise (economy as well). Does the WB 29cdi seem a good choice or should I go for the WB 34cdi? Is oversizing a problem?
the worcester is a good choice, they are reliable quiet and give a good bang for the buck,you'll find they fill a bath a lot qucker than your old slime boiler, and in my opinion the 34cdi would be worthwhile the extra cost, the heating side does't matter because even the smallest combi will do the heating no problem, its the dhw that needs the big input to give a good output,
One word of advice actually maybe two or three lots, since you have 11 rads you may need an extra expansion vessel on which ever boiler you have, also make sure that when completed you receive a certificate of compliance from building control, this is initiated by the gas safe registered engineer when the work is completed. You should receive it within 1 month of completion, don't let him forget, remind him it only costs the installer £2.50 so its important to get him to do it. A magnaclene on the boiler return is good too, and a limescale reducer. the boiler will need a bigger gas pipe size going from the meter to where ever boiler is, so that is a cost consideration. they don;t always remember to check that.
Peter, Are you saying that the 29cdi or the 34cdi will need a bigger gas supply pipe?. The spec for both states 22mm which I already have.