Hi to all. I have an Ideal classic nf40 boiler which I believe is a fully pumped system. The problem is when we switch on the programmer and request the CH nothing happens, this started about 6 months ago but at first it would eventually fire up but this past week it hasn't. After a lot of investigating I decided to buy a new room thermostat which made no difference. After more checks I thought I had narrowed it down to the diverter valve which was an acl 3 port mid position valve. I replaced this with a sunvic sdm1901 and I thought this had solved the problem as it fired up everytime I tried it. However the problem now is that the room stat will not shut off/ fire up the boiler although it still clicks , I have no control over the room temp. I checked all the wiring and found that the cylinder stat demand and satisfy wires seemed to be the wrong way round so after swapping them found that the CH works fine but the hot water has stopped working and the diverter valve isn't in the position it should be (mid) for CH/HW. I apologize for blabbing on but it's baffling me and thought it best to give as much detail as poss. I would be very grateful if anyone could suggest what the problem could be many thanks Daveym