guys,
i have the above boiler, and before xmas had a problem where i had no hot water, i called an engineer who replaced the diaphragm and piston on the 3 way valve between the CH and DHW. for this i payed a lovely sum of £240! and i still have an intermittent fault.(he did say it might not fix it when he finished..) i am therefore wary of calling them out again until they have replaced every part!

when i switch the shower on, if i alter the temp of the water the boiler drops out and i get cold water. the only way to get it back is to either get out and turn a tap on or to turn the shower off then back on again.

the flow switch is fine, but i do have a small leak somewere as there is a small drip every day. also i have to recharge the system every 2-3 weeks. is there anything i can do or do i bite the bullet and ring an engineer..

thanks in advance

stuart

finchy2k40, March 2010

forgot to mention on your boiler the leak could be one of the numerous rubber o ring seals that are fitted to these boilers as the valve assemblys are made of plastic and are held together with large spring clips which compress the parts onto the o rings just remove the outer cover by undoing the screws on the bottom of the boiler then lift the casing off the top hooks at rear of boiler then draw forward next the control panel will draw forward and down if you release the plastic clips on either side of panel top corner ! Now you can see all the valve assemblys one on the right is the diverter assembly and also the inlet restrictor ect the left is what i call the thermistor housing block look for all the spring clips because where they are is where all the o ring seals and washers are good luck at least you will know where the leak is coming from and you can give some indication to the engineer

STEVE, April 2010

your shower could be the problem if the boiler does not cut out while you are using the hot water taps in the house ! The shower mixer will have check valves fitted in the hot and cold water inlets if these are stuck open this can cause a backflow of cold into the hot water side of the mixer pushing the hot water back to the boiler and can cause the boiler to shut down on the hot water ! If you have different pressure on the hot water and cold water inlets to the mixer this can make it worse normally on combis the dhw feed is governed down to a certain bar pressure and you should fit a pressure reducer to the cold water side of the mixer to match the hot water pressure .unfortunately the only way to sort the checkvalves out is to remove the mixer the valves are usually fitted in the inlet connections to the mixer body ,once removed pull the inserts out and clean them or replace them .If this is not the problem then check that the flow restrictor in the boiler has not clogged up

STEVE, April 2010