I've just had a Worcester Bosch Greenstar 42CDI combi boiler installed (replacing my old traditional system). The problem we've got is that the gas fitter (who's Corgi registered etc) only measures 14 mb of gas pressure at the meter - he needs 18mb in order to commission the boiler. We called Transco and they came round and said there's no problem with the supply - they measured 30mb from the pipe going into the house and according to them they're only obliged to supply 19mb, so there's nothing they can do. They reckoned the boiler's too big (and that modern combi boilers are putting too much demand on existing domestic systems), although it was 8pm on a saturday night and they were on call so I'm reluctant to believe all they say. I've got a three bed semi, which I could easily put a loft extension with en suite into so I should be entitled to use a larger domestic boiler. Either way, I'm stuck with a boiler on my wall that we can't return but we also can't use as the gas fitter can't sign it off. Has anyone had a similar experience or got any advice? Is there a part that can be changed to downgrade it to a 37CDI for example?Cheers.