After having searched this forum for any recommendations for plumbers before and seeing quite a few posts seeking info - I can recommend a plumber that I've just used.
Our boiler died and we needed one quickly so I found one from yell.com. The company name is Unwins and they do work in the SE1 area ( and other areas).
We had a condensing, combi boiler fitted, with a water softener. He came and did it on a Saturday ( so saving me having to take a days holiday). Have to say, even though it wasnt dirt cheap, for the service we got - I think we got a pretty good deal. The guys name is Mark Unwin and his number is: 0500 130907.
I had a problem with Mark Unwin. He charged a surprisingly high amount for replacement parts for my boiler. I checked the price of the parts with a local supplier and discovered that they were a lot cheaper than he had claimed on his invoice. I paid Mr Unwin for his labour (which he had listed separately) and for the prices of the parts given by the supplier. I then offered to pay him the full sum listed on his invoice if he could explain why I appeared to be paying a premium. He never replied.
Draw from that what you will, but I will not be using him again.
Always good to hear of a reliable tradesman, esp a plumber.
Jack, I don't quite understand why you would expect the plumber to charge you his cost price for parts without adding a margin? Perhaps if you do not want to pay for his parts margin you should have bought the parts yourself and then asked him to fit them - but then he would be unable to guarantee his work on parts not sourced by himself for obvious reasons
bmovie, perhaps I have misunderstood the point of separating parts and labour. But even so, the figures on the invoice bore no relation to the cost price. One part was 35 per cent more expensive than the supplier's price, while another was 135 per cent more expensive.
I should say that he did indeed fix the boiler. Whether there are more competitive tradesmen who could do it for less than £517 is another matter.
Perhaps another analogy is taking a car to be serviced. A spark plug costs a garage around 29p but the price that appears on your invoice is 3.40 - a healthy mark up. I would not expect to be charged 29p
A normal tradesman's mark-up on materials is in the range 15-25%, to cover the costs of buying them, cashflowing the purchase etc. I would expect a good tradesman to be upfront about their margin. This guy seems to have been trying it on.
Some things i'm aware on with trade v charged price
London: every visit to a trade counter costs 1 - 2 hours of journey time - and that's assuming there are no delays.
If a part goes wrong then there are diagnosis time costs and again trade counter travelling time to buy a new part (assuming it is in stock!!). If problem/diagnosis was out of hours then a 2nd visit after purchasing part would be necessary. All of this to be under warranty of course at no charge!
If the customer purchases the parts themselves then upon failure all diagnosis, obtaining and fitting parts are to be potentially charged at several hours labour and part cost - ouch!
Tradesmen purchasing parts are using their skill set to be assured all components are in place as opposed to customers purchasing items and often missing key parts to lack of experience etc.
Sometimes different margins are put on different items due to how robust they're deemed, but usually only within large companies.
Another consideration is that providing say GBP1000.00 of materials for a boiler means the tradesman is taking a risk of his own cash. More paperwork to do and declare and the risk of loosing his own actual cash.
Life would be so so easy if all the tradesman would do is turn up with tools and 8am and leave 5pm without a thought about needing this n that or what to get tomorrow to be assured the job stays on track. No receipts to worry about, cheaper accounts' bill, smaller office, less admin staff etc etc
I'm not sure what value you put on all this but noting the warranty/insurance of parts, that alone is a fair figure.
You suggest that Mark Unwin charged a premium on parts because of the risk of having bought the wrong ones. The problem with that argument is that he did not carry any financial risk. If he had bought the wrong parts, he would have returned to the supplier, exchanged them and then charged me another £100 for the extra labour.
Second, your explanation of why he charged a higher premium on some parts than others is somewhat unscientific. It should be noted that he charged VAT on his notional prices. It seems more likely that his calculation of the cost of the part involved a bit of rounding up, to the tune of £70 (ie increasing his profit margin by 13 per cent).
My point is that if you are going to separate parts and labour costs, you should be scrupulous about it.
Finally, £517 seems to me excessive for two half-days of work to replace a fan and air pressure switch. I don't know what you mean by "warranty/insurance" of parts, but he gave me no such guarantees.