Please help me understand the central heating...

Alex1983

Sounds like 2 2 port valves, look at google images at 2 port valve.

Purple-flower

Thank you everyone for the responses! I replaced the programmer with a new one. Turns out the backplate was standard and had the same schematic so I could just slip on the new one.

I'm hoping to bleed and balance the radiators tomorrow because at the moment only one radiator is hot and the rest are cold. The pipes from the boiler are hot but the pipes to the radiators are cold

Ugh! So much effort!!

Le_Kirk

Do you have Thermostatic Radiator Valves (TRV's) on the rads and are they open? If you don't have TRV's are the lock-shield valves at each end open fully?

Purple-flower

Le_Kirk wrote: »

Do you have Thermostatic Radiator Valves (TRV's) on the rads and are they open? If you don't have TRV's are the lock-shield valves at each end open fully?

The rads have TRVs, I went round them all this evening and some were stuck in a down position but I managed to free them so they are springy. They don't go all the way down though but I'm not sure if that might just be the way they were made?

Another thing is I looked at the boiler and it seems to be set to "gravity". I was sure the system was fully pumped because there is a pump in the cupboard with the water cylinder. Pump looks like this one:

http://www.screwfix.com/p/grundfos-ups2-15-50-60-pump-head/34903?tc=CA2&ds_rl=1249481&ds_rl=1245250&gclid=EAIaIQobChMIvbihyuDN1wIV5pXtCh3n9AWIEAQYAyABEgL72PD_BwE&gclsrc=aw.ds&dclid=CM7XvNjgzdcCFWSt7QodpggLag

The previous programmer and the new one are both set to fully pumped? Does this create a conflict in the system?

Alex1983

You will have a pump with gravity and fully pumped.

You have said you have 2 valves in the airing cupboard with actuator writ on so it sounds like you have a fully pumped s plan system.

What boiler do you have, where does it say gravity.

Purple-flower

Alex1983 wrote: »

You will have a pump with gravity and fully pumped.

You have said you have 2 valves in the airing cupboard with actuator writ on so it sounds like you have a fully pumped s plan system.

What boiler do you have, where does it say gravity.

Hi alex1983, sorry for the delayed response, the boiler is a "potterton profile". There is a red switch at the base for the selection of gravity or fully pumped.

Alex1983

That selector switch is what controls something called pump over run, don’t worry to much about it. If the pump isn’t wired back to the boiler it will do nothing anyway.

Purple-flower

Thank you Alex

I have some images of the system:

Alex1983

Yes it’s definitely a fully pump s plan system. Very standard and good system.

Purple-flower

Le_Kirk wrote: »

If the programmer was disconnected, it is possible (depends how it was done) that the power to the 3-port valve has been lost and it is unable to move to CH or BOTH and is stuck on WATER. Does it have a manual mode, i.e. a little black lever that you can move to mid-position to check if hot water will flow through the radiators? I am assuming you have a 3-port or diverter valve as you say you have a hot water cylinder and I am assuming that the boiler fires up.

Alex1983 wrote: »

Yes it’s definitely a fully pump s plan system. Very standard and good system.

Is the actuator at the top (image 3) responsible for the hot water always being on or is it the one below? Should the lever be left, right or central?

some additional info, I have checked both boxes and the levers are both in the "B" position.

I had previously mentioned that I think a lever came off one of the actuators into my hand, it seems that there may still be enough left to move the switch if needed

Sorry! further update, I am learning all the time! With regards to the actuator at the top (that is going into the cylinder), the lever to control it manually has indeed broken off. On the side where you have A and B, the indicator is still visible.
I have observed it over time and both actuators stay in the B position and do not move. I am led to believe that because this is so, there is a constant demand on the boiler for hot water and it is bypassing the programmer controls. I can constantly hear water going through the cylinder.
However, I am not sure why the radiators are not always on, by the same principle?

It seems that one or both actuators will need to be changed, but in the meantime, is there anything I can do to stop the constant heating of the water and save some money? ( Will I be able to flip open the actuator box and manually free the lever?)

Thanks everyone!