Worcester 30cdi or 30si boiler?

josiejump_2

I've recently had a new Worcester condensing boiler installed with piping upgrade throughout the house and new rads. However, the wrong boiler was fitted in error (I'd gone for the Worcester 30cdi option but the fitters misread my email!). The error was only realised at the point they were ready to leave.

While I was assured that there was little difference in spec (and a £200 saving), I've looked at the Worcester website and am concerned that the si boiler range is suggested for 'apartments and small to medium properties' and the CH output of the 30si boiler is cited as only being 24kw. Is this sufficient for a fairly large 4-bed, 1 bath semi (11 rads)? The fitters say it is but that they are happy to replace if I want to, at the extra cost. I don't want to go to the hassle if what we have is good enough.

Can anyone advise please?

southcoastrgi

I assume it's a combi you have ?
the slight confusion is because WB stopped making the 30cdi over a year ago

josiejump_2

Oh really? Yes, it's a combi. The fitters quoted for both models and actually advised me to have the 30CDi (to replace a very old and knackered Worcester 350 combi). They misread my response and installed the 30Si model - the mistake was only realised as they were going through the instructions with me before they left and I picked up on it.

They told me that the SI was essentially the same boiler but slightly noisier (not an issue) with facility to control the water temp which they said the 30CDi doesn't (so a 'pro' in favour of the Si model). However, they didn't tell me that the 30Si only has 24kw CH output, which has caused me some concern. I have queried it with them and they tell me it will be sufficient as each rad requires 1.5kw and an additional 2kw for the hot water.

No mention of the fact that WB no longer do the 30CDi though! I guess they have some in stock.

southcoastrgi

rule of thumb

all combi's will be big enough for the heating system, if your heating requires more than the combi output then a combi isn't suitable for your house anyway

the SI is the brand new model, supposedly designed by installers from the feedback WB have recieved, they come with a 5 yr warentee so make sure your installer reg the boiler with WB, i haven't worked on one yet so don't know if they have improved things,

but to answer your question yes i would say from this side of the keyboard that 24kw is enough for your heating

southcoastrgi

oh josie, josie, josie

"Ok, so looking at the CORRECT instruction manual now I note that the 30CDi condensing combi stopped being manufactured last year!"

I think this is what you are looking for :rotfl:

josiejump_2

Erm, banged to rights (though I did check with the manual after you told me!)

Anyway, thanks for your advice. I think you know what I've decided to do