Why did my plumber install a Combi boiler, when I asked for a System Boiler?

saintpatrick

Morning all! Sorry about the title - its a bit niche I expect but I would respect another view (or ten!)

I agreed a new System boiler with my plumber who is experienced and gets decent reviews. This was to replace an older System boiler that had failed. His son, who works in the family business, fitted a Combi while I was at work. Same efficiency, kW output, thermal units, size, branding as the model I had shown to his father when quoted. The Combi is linked to the existing cylinder from the previous circuit and thus delivers hot water as expected.

The instant hot water feature of the Combi is redundant with this install, as that output is not linked up to any taps or piping - there is no sink in the utility room adjoining the kitchen and new pipework would have to be laid into the kitchen infrastructure or into the shower of the bathroom above to avail of this feature.

The Combi has more pipework coming out of install than a System and will need to be hidden from view, and a testing valve or tap will need to be fitted to the redundant hot water outlet for regulation purposes (I'm told by Worcester Bosch Tech Support).

Please can anyone tell me honestly, why would he do this? If I'm being cynical, I may say that the Combi is £200 or so cheaper than the equivalent System, so he stays competitive in his quotes - but I accepted his quote after a System boiler was agreed... and it isn't true that he thought I wouldn't notice the difference, since he left the install documentation behind.

I'm upset that he has done this, but I'm trying to be reasonable in my response... Why should I let him do this? 

Eldi_Dos

Could you post up the model number of what you ordered and number of model installed.

Was the boiler delivered by courier before installer came and fitted it?

daveyjp

All down to what was specified and if you aren't happy you need to contact the engineer and tell them to fit what was specified.  However with no hot water demand the combi may be far larger than required so a lower output system boiler could be cheaper.

BTW when my wife needed a new boiler for her business premises the engineer did as above.  Fitted the lowest powered combi to meet the heating demand and isolated the hot water circuit.

Section62

plunketto said:

Please can anyone tell me honestly, why would he do this? If I'm being cynical, I may say that the Combi is £200 or so cheaper than the equivalent System, so he stays competitive in his quotes - but I accepted his quote after a System boiler was agreed... and it isn't true that he thought I wouldn't notice the difference, since he left the install documentation behind.

I'm upset that he has done this, but I'm trying to be reasonable in my response... Why should I let him do this? 

Rather than deliberate I'd suspect an error in ordering/shipping, and the son not being clued up enough to check the boiler before starting work, then ploughing on regardless.

What did the plumber say when you told him you wanted the new boiler replaced with the one you'd asked for?

Lorian

What make and model did you actually get, and please post a picture of the pipework under the boiler.

Risteard

plunketto said:

Morning all! Sorry about the title - its a bit niche I expect but I would respect another view (or ten!)

I agreed a new System boiler with my plumber who is experienced and gets decent reviews. This was to replace an older System boiler that had failed. His son, who works in the family business, fitted a Combi while I was at work. Same efficiency, kW output, thermal units, size, branding as the model I had shown to his father when quoted. The Combi is linked to the existing cylinder from the previous circuit and thus delivers hot water as expected.

The instant hot water feature of the Combi is redundant with this install, as that output is not linked up to any taps or piping - there is no sink in the utility room adjoining the kitchen and new pipework would have to be laid into the kitchen infrastructure or into the shower of the bathroom above to avail of this feature.

The Combi has more pipework coming out of install than a System and will need to be hidden from view, and a testing valve or tap will need to be fitted to the redundant hot water outlet for regulation purposes (I'm told by Worcester Bosch Tech Support).

Please can anyone tell me honestly, why would he do this? If I'm being cynical, I may say that the Combi is £200 or so cheaper than the equivalent System, so he stays competitive in his quotes - but I accepted his quote after a System boiler was agreed... and it isn't true that he thought I wouldn't notice the difference, since he left the install documentation behind.

I'm upset that he has done this, but I'm trying to be reasonable in my response... Why should I let him do this? 

Crazy suggestion I know, but perhaps you should ask him rather than internet forum users.

Eldi_Dos

Risteard said:

plunketto said:

Morning all! Sorry about the title - its a bit niche I expect but I would respect another view (or ten!)

I agreed a new System boiler with my plumber who is experienced and gets decent reviews. This was to replace an older System boiler that had failed. His son, who works in the family business, fitted a Combi while I was at work. Same efficiency, kW output, thermal units, size, branding as the model I had shown to his father when quoted. The Combi is linked to the existing cylinder from the previous circuit and thus delivers hot water as expected.

The instant hot water feature of the Combi is redundant with this install, as that output is not linked up to any taps or piping - there is no sink in the utility room adjoining the kitchen and new pipework would have to be laid into the kitchen infrastructure or into the shower of the bathroom above to avail of this feature.

The Combi has more pipework coming out of install than a System and will need to be hidden from view, and a testing valve or tap will need to be fitted to the redundant hot water outlet for regulation purposes (I'm told by Worcester Bosch Tech Support).

Please can anyone tell me honestly, why would he do this? If I'm being cynical, I may say that the Combi is £200 or so cheaper than the equivalent System, so he stays competitive in his quotes - but I accepted his quote after a System boiler was agreed... and it isn't true that he thought I wouldn't notice the difference, since he left the install documentation behind.

I'm upset that he has done this, but I'm trying to be reasonable in my response... Why should I let him do this? 

Crazy suggestion I know, but perhaps you should ask him rather than internet forum users.

Not particularly helpful reply to a first time poster.

People come on here for advice on situations they have not dealt with before and how to procede from there,thankfully there are many posters with experience in different areas willing to help.It is one of the things I like about this forum.

Albermarle

Same efficiency, kW output, thermal units, size, branding as the model I had shown to his father when quoted.

Normally a combi will be more powerful than a system boiler, so seems strange that they are the same.
Typical system boiler will be 12 to 18 KW and a combi 25 to 30 KW.

ThisIsWeird

Hi Plunketto.

Is he offering to reduce the installation cost by the £200? Or looking to pocket this difference himself?

And are you sure the two boilers are physically the same size? Usually a Combi is larger than a System type - there's more gubbins inside.

I presume the extra pipework is a cold mains supply, and a DHW outlet going to this 'tap' you mention is required - 2x15mm pipes? 

Any other potential issues, other than (possible) physical size and additional pipes? I'm guessing that the Combi, even tho' not used as such, will still be more complex and therefore more prone to going faulty. Did W-B make any other comments about using a Combi as a System?

You are perfectly right to feel miffed at this; at the very least they should have discussed this with you, explained their reasoning, and sought your approval.

It would help us to know the exact two models of WBosch involved.

"Should you let him do this?" That's entirely up to you. With everything now in place, a swap should only be an hour or two's work, assuming the flues are compatible sizes, so no excuse there; if you wanted to insist, I'm sure you could.

Please let us know the two models involved, and also what you are minded to do about it - surely at the very least a £200+ discount?

Do you have Legal Protection in your house insurance?

FreeBear

Albermarle said:

Same efficiency, kW output, thermal units, size, branding as the model I had shown to his father when quoted.

Normally a combi will be more powerful than a system boiler, so seems strange that they are the same.
Typical system boiler will be 12 to 18 KW and a combi 25 to 30 KW.

We have seen numerous posters here with a 30kW system boiler over the years. Very few homes need anything that big. Yes, you get fast reheat times for the hot water tank (say 10-15 mins instead of 30-45 mins). The downside is you need a boiler with a very wide modulation range to cope with the 4-8kW demand of the heating system.

plunketto had agreed to a 12kW or 18kW system boiler, then he needs to be kicking up a fuss and demand one is fitted. If he had agreed to a 30kW system boiler, then a combi set to heat only will do the job, but...

Section62

ThisIsWeird said:

...

Do you have Legal Protection in your house insurance?

First things first.... does the plumber know the wrong boiler has been fitted, and what does he say about swapping it?