Can't switch water off when Central Heating is on. Need help please!

[poni]

then it's pretty much 90% the valves are working

more like 50% (only two valves in the system), if it is gravity then you would have/need only one valve

 

[Creakyride]

I would not remove the cover ,just move the manual override leaver and you should feel it move the ball valve below ,it might come back on its own but you can lock it in the open position by lifting the leaver at the end of its stroke up or down into the notch at the end,

I just got my brother to do the manual actuation on the valve. We can hear the motor and releasing the lever it springs back to the original position.

Locked the manual lever up and then tried to disable the hot water from the programmer but doing so the CH got also disabled, so the valve lever has now been set to the original position.

Maybe I will buy a basic programmer from Screwfix and replace it, unless I find an installation manual of my existing one. So far I have only found a user manual EP 2000 but this does not show wiring diagram or removable jumpers.

 

[poni]

if you buy the same make, but a new one it should fit on the old back box no wiring involved

 

[Creakyride]

I think you’ll find this is a gravity fed system. ??

Unless I am wrong, this to me is a gravity fed system. I have 2 water tanks in the loft, for the hot and cold water. Many years ago I had to change a radiator and I remember, putting a bung on the inlet pipe and a batten under the ballcock arm to stop the water.

 

[Creakyride]

if you buy the same make, but a new one it should fit on the old back box no wiring involved

Oh! That's even better!
Does the front of the controller lift up or towards me in order to open it. Obviously I'll switch the fuse off first.

 

[poni]

there should be two screws at the bottom, undo them half way and lift from the bottom, do make sure it off at the mains first!!

 

[poni]

Unless I am wrong, this to me is a gravity fed system. I have 2 water tanks in the loft, for the hot and cold water. Many years ago I had to change a radiator and I remember, putting a bung on the inlet pipe and a batten under the ballcock arm to stop the water.

the small tank should be for the CH and to heat the water in the cylinder by a indirect heating coil in your hot water cylinder, and the larger one should be for the hot water to the taps,

 

[Creakyride]

there should be two screws at the bottom, undo them half way and lift from the bottom, do make sure it off at the mains first!!

Thanks Poni, I will give it a go tomorrow, after buying a new programmer.

One strange thing that happened when I was only using hot water (CH OFF), a couple of times the timer would not switch off at the given time, so I had to manually press the HW button to switch it the time off, so maybe the programmer has been faulty.

 

[Creakyride]

the small tank should be for the CH and to heat the water in the cylinder by a indirect heating coil in your hot water cylinder, and the larger one should be for the hot water to the taps,

So, does this setup shows that the system is gravity fed or is this irrelevant and that it could be either, gravity or pumped.

 

[Stevie G]

Hi Guys ,this system is not gravity fed ,as pump common to both HW & CH 2-port spring return valves . I take it the pump is fitted in the return pipework to the boiler ?
Call for HW on programmer, and prove valve opens and see if pump operates and boiler fires up.
On the 2-port spring return valves there is an Aux switch that makes (Closes Contact) when valve opens fully which should start the pump and enable the boiler to fire ! Depending how the electricians have wired the controls, the system is 37 years old and the controller shows it was manufactured in 1987 , i have known electricians not to use the aux switches as they never fully understood control strategy .
Hope this has gave you some food for thought !

Geoff 1946 is correct in summing up old gravity HW - pumped CH system .

 

[Creakyride]

So, would replacing the programmer help or not?

 

[Andy™]

So, would replacing the programmer help or not?

maybe. maybe not. replacing random parts is often an expensive way of fault finding

 

[Andy™]

I think you’ll find this is a gravity fed system. ??

gravity doesnt have valves, looks like a fully pumped S plan

 

[Barx]

Unless I am wrong, this to me is a gravity fed system. I have 2 water tanks in the loft, for the hot and cold water. Many years ago I had to change a radiator and I remember, putting a bung on the inlet pipe and a batten under the ballcock arm to stop the water.

This is a reply to @Sharpend too, but cannot figure out multi quoting at this early(ish) hour

Ok, maybe I'm not using the right terminology then. I know a gravity system as how they were with the old coal fires etc. Where there are no valves. The heat just circulates around the hot tank coil (HW only) and the pump is switched on for dragging the heat around the rads (HW & Heating).
The system the in the OP, I know as an open vent pumped s-plan system.

 

[Sharpend]

Now there was me thinking that gravity fed was because the mass of water is fed at gravity pressure ie without the mains pressure and pressurised tank!!
Perhaps I’m not as old as I thought!!

 

[Andy™]

Now there was me thinking that gravity fed was because the mass of water is fed at gravity pressure ie without the mains pressure and pressurised tank!!
Perhaps I’m not as old as I thought!!

gravity, S, Y etc plans are often all open vented, just different methods of the water circulating between DHW & CH

gravity no zone valves, just a pump on heating
S uses 2 port valves, separate valves for DHW & CH & fully pumped
Y plan uses a 3 port valve to direct/split between DHW & CH & fully pumped

also worth noting that solid fuel heating is always gravity - if the power /pump fails the pump will stop but the boiler will keep producing heat for a while, you need somewhere for that heat to go. so DHW side is gravity & doesnt rely on anything else to keep circulating

 

[Sharpend]

Thankyou Andy for clarification, I was aware of different systems but not the correct differentiation of the term gravity.
So even at the the ripe old age of half a century plus some, education is still much needed. Either that or the grey matter is diminishing in its ability to retain information??

 

[Murdoch]

Bet the OP is more confused now!

 

[Creakyride]

This is a reply to @Sharpend too, but cannot figure out multi quoting at this early(ish) hour

Ok, maybe I'm not using the right terminology then. I know a gravity system as how they were with the old coal fires etc. Where there are no valves. The heat just circulates around the hot tank coil (HW only) and the pump is switched on for dragging the heat around the rads (HW & Heating).
The system the in the OP, I know as an open vent pumped s-plan system.

I saw a video on YouTube last might and the guy was illustrating the different system types.
My system seem to match the S plan type.

My hot water is definitely not pressurised as I have an electric power shower.

So, yes, I have to say that it is a Gravity fed HW with a pumped CH, S plan system.

I think I will splash out on a replacement controller as it at times don't obey the HW clock time, it doesn't switch off when it supposed to, hence I have to press the button myself. Also, I didn't even know there was a battery in there, so that would need to be replaced.

I will also check for the correct fuse rating, as it should be 3A.
Apparently the controller it's likely to be damaged if any other rating Fuse is used.

 

[Mike.J]

Have not read the whole thread, but the synchronous motors on the zone valves are a regular replaceable item, but do usually fail closed, I would suggest that the hot water zone valve is being by passed due to wear of the rubber valve ball being pitted, yes they are a type of rubber ball.