Apologies in advance for the long-winded waffle...
So, our house was until recently heated by a coal stove with a back boiler, connected to 5 radiators on a pumped circuit. Last August we had the house connected up to the gas mains and got a few plumbers to quote to install a gas boiler, upgrade some of the pipework, replace three of the existing radiators and add three more.
We went with a guy who quoted £4k, but seemed more interested in doing a good job than the others, and seemed to really know what he was talking about when discussing the various options. He had some other jobs on as well, so couldn't devote 100% of his time to us, and wouldn't commit to a firm completion date. He started on the 8th September, and we asked him to finish by the 8th October, and he said that he expected to finish "probably well before then", but couldn't offer any compensation if he didn't finish by then. Our priority was to get it finished by the time it got cold, so that we would be warm and could crack on with boxing in etc., so accepted the somewhat vague timeframe.
Since then he has worked in fits and starts, often doing nothing here for two weeks on end. We only had a few radiators working for much of the time until soon after Christmas, the spare bedroom was out of action for most of the time (to give access to pipework, loft etc.), and it's only a couple of weeks ago that the system has been pretty much fully functional. There are a few minor jobs left (like fitting the room stat in its final position, final balancing etc.), and it's now over 5 months since he started. We have been pestering him constantly the whole time to get him to crack on and finish, but haven't wanted to ditch him because (a) his work, when he does it, is of good quality - absolutely no complaints there, and (b) until he finishes the system and signs off on it, we'd be in a bit of a pickle trying to get a different installer to finish off his work and sign off on it (and there could potentially be warranty issues with the boiler).
Now, we agreed at the start to pay £4k for the work to be done, under the understanding that it would take a few weeks. According to the CAB website, even if no specific completion date is specified, consumers have a right to expect a job to be finished in a reasonable timeframe.
I don't believe that we should let ourselves be taken advantage of like this. If the quote had said "£4k, but it will take 5 months" then we would absolutely have turned it down and gone elsewhere. Realistically, even if the quote was "£2.5k, 5 months" then we would have said no. He has been going to other (presumably more lucrative) jobs whilst not at ours - so he has been making money by messing us about. It's not that he's been sick or anything. When pressed he mentions the snow (he comes a fair way out to our place), which would be valid for a couple of weeks, but not a 4 month delay - there was certainly no snow around in September when he should have been finishing up.
So, I've suggested that we negotiate a fair fee. In my view, £2.5k would be fair, but I doubt he'll agree to that - that would be a big decrease. Realistically I think £3k would be a reasonable compromise.
What do you guys think? Am I being an unfair customer from hell, or do I have a reasonable case? I intend to talk to the CAB to find out what they advise. I'm only interested in a fair outcome - absolutely not trying to screw him over, but don't want to be screwed over myself!