Weird heating system

[Leethomp]

Im just wondering if anyone can give me some advice as had 2 plumbers round and still getting same issue. Ive recently loved into a new house and the heating system is doing something weird. It had a new worcester bosch boiler a couple of years ago and heating system seems in good order. But.... When heating and hot water are on together the rads seem to only be warm and one sometimes doesn't heat up at all. Just the one... However as soon as hot water goes off all is well and rads go roasting hot . Ive looked at the motorised valve and it seems to be moving, but i don't know, maybe not enough... Any help would be appreciated . Thanks all

 

[Keefy]

Might sound daft but first of all - are the valves open either side of the radiator that's not heating up?

 

[ShaunCorbs]

Sounds like the cylinder is taking all the flow / heat so best to stagger the hw / heating times turn the hot water on a couple of hours before the heating is set to come on

 

[leethomp]

Sounds like the cylinder is taking all the flow / heat so best to stagger the hw / heating times turn the hot water on a couple of hours before the heating is set to come on

Is there anyway to correct this ??

 

[ShaunCorbs]

Is there anyway to correct this ??

Can’t you stagger the heat up times ?

 

[Chuck]

Is there anyway to correct this ??

As @ShaunCorbs has already indicated, the simplest/cheapest solution is to programme the hot water so it heating occurs at a time when you are not using the central heating. For most people, this means have it on for a couple of hours between 0530 and 0730hrs.

 

[Deezell]

Is there anyway to correct this ??

Is there anyway to correct this ??

1. Turn up the pump pressure, if it has a three position switch, or else use a pump with higher pump head pressure.
2. Introduce a balance valve in the HW cylinder flow. These are likely 22mm pipes, which present a much lower resistance to flow than the CH 15mm, and especially the CH 10mm microbore.
3. Ensure the three position valve is correctly wired to receive a HW satisfied voltage from the HW cylinder stat normally closed to the valve grey wire, which will at least close the HW branch of the valve when the cylinder stat is satisfied, even if your HW timer output is live.
4. Introduce priority CH which only allows HW to occur when CH is satisfied by linking the grey valve wire to the CH call for heat after the CH thermostat, the white wire This will change the CH call from moving the valve to midpoint to moving it to CH only. HW heating will resume during the off cycles of CH if a HW timing event is on.

 

[Timmy D]

Add a valve to balance the hot water cylinder so it doesn’t steal all the flow.