DIY Doctor UK DIY Forums

i have just switched my central heating on for the first time this year,problem is rads got hot but no hot water . Looked at ma1 and was in h position all time even when only water was selected . Took off plastic box and valve moves free enough but motorised switch doesnt had a bit of a play with it and now works , but not sure if problem will reoccur ? noticed some one else had same prob is there an alternative replacement which is more reliable that will fit straight on valve . thanks :roll:

The problem may not re-occur ever again, but there is a good chance it will.

Screwfix sell that valve so you can buy one and save yourself a drain down by just fitting the top electrical part. This will probably solve the problem, but if not you can easily replace the whole assembly.

Honeywell do a similar product, that is probably more popular, but the threads are different, which means removing the olives from the existing pipes, which is doable, but more difficult than a straight swap.

thanks plumbbob it did happen again this morrning played with plastic lever at bottom of box and started to work again .What does lever do as no matter which position lever is in switch for w/m/h will not move by hand thanks

The lever is for operating the ball valve assembly manually. If this lever is totally floppy, or is stuck and refuses to move even slowly, then the internal gearing is shot and the valve needs replacing. (Well the gearbox anyway.)