Ideal Isar Faulty Diverter Valve - Please help!!

[WoolleyJo]

I have a Ideal Isar H35 combi boiler and have had a problem with the radiators being warm intermittently even when the timer is switched off! I've spent ages researching this and experimenting and have decided its the diverter valve within the boiler thats at fault. When the boiler ignites to heat the water (showing 't' on the display) a small amount of hot water is escaping into the radiators and heating them! I'm a single mum with very little cash so this is scary stuff!! Can someone please advise wether I need to replace the valve in its entirety or just the cartridge?? How much should I expect this to cost?? Any advice gratefully accepted!!!

 

[shambolic]

If its the grey square head on the diverter then it will only need the internal honeywell cartridge

not expensive part and 20 mins to change.
174200 part number

 

[WoolleyJo]

Hiya
I have been very lazy and only just got around to buying this part! My dad is going to replace it and has downloaded all the relevant info!! I have just one quick question - When we open the diverted valve housing to replace valve cartridge, do we need a new gasket to seal it again???

Can you please advise before we go ahead with the work??

Thanks

 

[45yearsagasman]

The cartridge has an O ring seal fitted and I would advise you to smear it with silicone grease to aid fitting.Depressurise the boiler first and ensure no electrics get wet.