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    Worcester 28CDi combi boiler over pressurising

    I'm no expert here, but I've had a lot of trouble with my 28CDi (including pressure problems, thankfully fixed except for a slow loss of pressure over a few months) and am very interested in what's going on. If the mains water is turned off to the whole house at the stopcock (which I assume...
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    Worcester 28CDi combi boiler over pressurising

    If I understand correctly the pressure continues to rise even with the heating off AND mains water inlet off (not just the key removed from the filling loop) so water cannot be getting into the system. What about a faulty pressure gauge?
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    Worcester Bosch 28CDi combi boiler hot water flow problem.

    My 28Cdi behaves similarly (although probably not as bad) and I had the diverter valve and water to water heat exchanger replaced a few months ago. I don't think my water pressure is what it should be though, and it does vary quite a lot. But if the water temperature is not steady at a given...
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    Pressure guage on Worcester 28i Combi Boiler

    I had a similar problem with my 28cdi losing pressure which turned out to be a combination of problems, one of which was the expansion vessel. It was slowly filling with water, which made the pressure fluctuate to the point where it was zero when cold but reached over 3 bar when hot. Had it...
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    Worcester 28CDi Automatic air Vent Leak, Sudden & Severe

    You seem to have had a serious pressure problem as the pressure relief valve is rated at 3 bar and should have blown before the automatic air vent which is rated at 10 bar. Perhaps the prv jammed, but neither are servicable and should be replaced because both are prone to leaking after...
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    I had my diverter valve replaced a couple of months ago and the engineer also replaced the water to water heat exchanger because it was scaled up and reducing the flow. Perhaps they don't want to do this as the part is expensive.
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    How long to heat a room from 16c to 21c?

    That sounds logical to me and may well be my problem, although I haven't been checking what the outside temperature has been when the room's been +16°c. I wonder the insulation specification is in order to achieve +21° inside when it's -1° outside? I would have thought the better the insulation...
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    How long to heat a room from 16c to 21c?

    Yes, a Honeywell CM927. I removed the TRV from the rad in the room when I got the thermostat. My bay is also box shaped but upvc double glazed on 3 sides, and is the only outside surface. The room is nearly north facing though, which doesn't help. The curtains are cill length, good quality...
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    Worcester 24CDi Problem - any advice please?

    A manual can be obtained here:
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    How long to heat a room from 16c to 21c?

    The thermostat is in the room I'm measuring. How can I tell if it's cycling? Draughts may be a problem, but do we keep the door closed. The curtains are usually closed by the time the heating is on full, and I always make sure that no heat is getting trapped behind them. The system is...
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    How long to heat a room from 16c to 21c?

    This may be a "how long is a piece of string" question, but how long should a room about 12' by 13' with solid walls and a bay window take to heat up from 16c to 21c? I know it's been cold recently, but it's taking 4 or 5 hours or so which seems excessive. The radiator, which is a double 160cm x...
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    Optimum CM927 settings for fuel economy with WB 28Cdi?

    That's exactly what I've done! It hit me last night when I was playing with it. However, what I'm trying to work out is what is most energy efficient in a house with uninsulated 9 inch sollid bricks walls. I'm sure I've heard somewhere that because the low specific temperature of solid walls...
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    Optimum CM927 settings for fuel economy with WB 28Cdi?

    Now now boys, let's not fall out! I don't know when the regulations changed, but when I installed central heating in my first house in 1981 (never again!) I got a gas fitter to connect the gas to the boiler and commission it even then. I'd never touch gas, but I suppose it depends on how you...
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    Optimum CM927 settings for fuel economy with WB 28Cdi?

    And they say Americans don't understand irony! Assuming you are of course. Unfortunately I've got a wife who should really be living in a tropical climate. Hmmm, now there's a thought for saving gas................
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    Optimum CM927 settings for fuel economy with WB 28Cdi?

    I'm about to fit a Honeywell CM927 programmable thermostat to my Worcester 28Cdi. We have 10 radiators (includes 2 large doubles and 4 smaller doubles), all fitted with TRVs except in the bathroom. I know the system is out of balance because the rads heat up at different rates. It's a 3 bedroom...
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    Wiring Honeywell CM927 to Worcester 28Cdi

    Many thanks for the prompt replies both of you. I presume you mean you split the live instead of linking any terminals on the box. And I need to follow diagram 4a instead of 4b which did cross my mind! Hard to believe I know, but I haven't. Putting it right now though! Yes, it...
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    Wiring Honeywell CM927 to Worcester 28Cdi

    I'm replacing a Honeywell ST6100C timer with a Honeywell CM927 programmable thermostat to a Worcester 28Cdi. Can someone please advise on the correct wiring, as the wiring diagrams in the installation instructions and on the reciever box seem to conflict on which live terminal to use on the...
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    Leaky Worcester

    Robbie, I can't reply to your PM because we're not "friends".
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    Honeywell CMT927 or CM927

    Can anyone please tell me if the Honeywell CMT927 and CM927 programmable thermostats are exactly the same item with two part numbers? Or is one number an earlier model and if so which one? Thanks