Which new boiler

[chrismcc]

I have just has some quotes for a new combi boiler and central heating install but I don't know which boiler to go for. I live in a 3 bed double glazed semi with cavity wall insulation. There is a total of 10 radiators and I have an upstairs bathroom with a shower over the bath and also a downstairs shower room. The various qoutes specify the following boilers:
Worcester 30si
Worcester Greenstar 37CDI
Vaillant Ecotec Pro 28
Vaillant Ecotec Plus 837
Vaillant Ecotec Plus 937

There seems to be quite a lot of difference between these boilers and I am not sure which I should go for so would welcome any suggestions.

Thanks

 

[gas4you]

The 30Si is a system boiler, so will need a hot water cylinder of some sort.

Forget the Ecotec Pro, total waste of time, designed for the new build market and cheap cut down version of Ecotec Plus. Also only has a 1 year warranty.

37CDi powerful combi, as is the 837, only really needed if you have baths mostly or need to feel 'sand blasted in the shower.

937 is a storage combi, massive lump on the wall, but high flow rate.

Last 3 will need gas pipe uprated from meter probably and at leats 16 l/min cold mains supply and at least 2 bar, 937 needs at least 20 l/min and hopefully around 3 bar pressure.

Why have you not been explained to from the 'quoters' about the boilers they are suggesting

I always do when I do a site visit and quote

 

[bengasman]

Easily the 37 cdi. Vaillant used to be similar quality but since they have joined forces with gw and the likes, not what they used to be.
Wb after sales unrivalled.
You could go for the wb system boiler but to get it half right you would need a proper unvented cylinder installed, which makes it at least a grand more expensive

 

[bigdek]

The 30Si is a system boiler, so will need a hot water cylinder of some sort.

The 30 Si is a combi . Basically a junior with a dhw temp control knob .

12.3ltrs at 35 degrees

 

[gas4you]

Oh yeah, but then what would I know about WB, I would never fit the c r a p

 

[chrismcc]

Thanks for the info so far. I haven't spoken to any of the guys that have been round personally as I've always been at work, the missus has dealt with them, I've only seen the quotes. I did speak to one of them on the phone whilst at work as the wife was trying to explain that the existing CH system is on a single pipe, 15mm all the way round, but he didn't believe her so she phoned me and told me to talk to him. I told him to go upstairs and look on the floor in one of the bedrooms which I had just had up, where I had marked the exact position of all the pipes and cables. His response was "are you sure it's a single pipe system 'coz all the rads have got two pipes coming out of them"! Needless to say he wont be getting the job. Anyway, back to boilers, I've had a Vaillant in the past, a 242E something or other and fixed all the water side faults myself. It had a new DHW heat exchanger a couple of DHW microswitches, a new diverter valve and a new diapraghm in the 10 years we had it. On the whole though it was pretty good but the hot water flow rate wasn't up to much. I now have two kids (who like baths) and I and the wife like the shower but with the washing machine and the dishwasher on a lot we have to time our showers at the moment so we want something with decent DHW performance. I've seen people praising the Worcester Bosch and people who don't like them. Similarly with the Vaillant. I have enough room to mount a largish boiler if need be but not enough probably to fit in a storage tank. Gas supply is not a problem and although I haven't checked, I think our water pressure is fairly good. Other than the boilers I've been quoted for would anyone recommend anything else?

 

[chrismcc]

Just checked the flow rate from the kitchen tap and got 16 litres in 62 seconds. It's a mixer type tap with small bore pipe through so I don't know if that makes a difference.

A bit more testing this time from the bath tap and I got nearly 20 litres in 1 minute so I guess the flow rate is OK. How do I test the pressure?