Hi New to Forum Need Some advice Re Central Heating

[Twitch]

I have noticed a couple of my rads are cold when the system asks for both Hot Water and Heating yet when system asking for Heating alone all my rads heat up. A friend suggested it could be my diverter valve in airing cupboard so I tried switching between water and heating and valve does move to the mid position when both HW & Heating called for could it still be faulty? or is it likely to be something else appreciate any advice.

Twitch

 

[Theorysparky]

sounds like the diverter valve to me

can you move the lever on the silver box on the valve ????? is there tension ???

 

[Twitch]

Hi

Just checked and yes there is tension

 

[Theorysparky]

ok then

have you bled the radiators ????

has this only happened since you have started using the heating this winter ?????

are all the radiators open ?????

 

[ga55man]

sounds like it could be either a problem with the pump or the flow pipe to the heating side has a slight blockage allowing the heat to push down the coil on your cylinder faster than through the heating circuit and returning to the boiler thus shutting off early as satisfied on the thermostat.

try choking down the valve {gate type on the cylinder for a while allowing it to push through the heating cicuit ! if it works then i would recommend a chemical flush of the heating system !

 

[mikep]

Pumped water will always take the easiest route, on the older system it is pumped from the boiler to the airing cupboard to 2 zone valves one opens and lets it circulate through the radiators, when the hot water cylinder thermostat calls for heat it opens the other zone valve which lets the water circulate through the heating coil of the hot water cylinder heating the water, because the cylinder is a short route it returns back to the boiler, so it circulates much easier through this coil so slows down the circulation through the radiators which is normally the furthest ones away, Normally fitted is a valve inline to the cylinder heating coil to restrict the flow so as to keep a good flow through the radiators by forcing more water through them.

If it has this valve then turn the heating off, call for hot water so as to circulate the hot water through the cylinder start closing the valve until you hear the pump change note this shows that you are restricting the flow through the cylinder then simply open it a touch until the noise goes, this shows that it is at the point of being slightly choked giving more flow to the heating when that comes back on, That's it.

Hope it helps.

Mike.