W-plan pump run on

[davidwf]

not sure, no.......report was "the tops are getting hot" so one would assume they arent ring supplied all the time the HW is running or else they would be very hot all over

One other question.... around the diverter pipework is a 15mm bypass....as he doesnt have any TRV's can I close this off?... it is about 2 turns open at the moment

 

[John.g]

It should be OK to shut the bypass since the water allways has somewhere to circulate.

 

[ShaunCorbs]

dunno.... I will have to check where the cables go and also what is wired to where....what a nightmare 😡
....but even if the roomstat goes to the boiler (which I am prtetty sure it doesnt) , as it is not calling for heat it shouldnt matter

No but the valve for heating to open eg heating on is fed from the cylinder stat satisfied so every time the cylinder is satisfied the valve opens for heating

When in reality it would send power to the prog room stat and then the valve etc

 

[ShaunCorbs]

not sure, no.......report was "the tops are getting hot" so one would assume they arent ring supplied all the time the HW is running or else they would be very hot all over

One other question.... around the diverter pipework is a 15mm bypass....as he doesnt have any TRV's can I close this off?... it is about 2 turns open at the moment

Yes as one port is always open

 

[davidwf]

I THINK I have re-drawn it correctly "as-is".....without programmer connections etc.

IF correct I agree there's no way the diverter can be operating....
how about IF any of the cyl stat connections are reversed.....
appreciate thats a lot of IF's but I havent been able to get over there yet

 

[ShaunCorbs]

You sure your drawing is correct 100% as your boiler requires a perm live and a switch live ?

You sure the red wires arnt perm lives ?

 

[John.g]

I THINK I have re-drawn it correctly "as-is".....without programmer connections etc.

IF correct I agree there's no way the diverter can be operating....
how about IF any of the cyl stat connections are reversed.....
appreciate thats a lot of IF's but I havent been able to get over there yet

View attachment 94764

That looks correct to me, when you do get there suggest turning both roomstat and cylinderstat to a high setting, when pipe B? to the cylinder coil gets hot about a foot from the diverter valve (and pipe A remains cold, turn roomstat to a low setting (no call) then turn down the cylinderstat, check that pipe A remains cold during boiler overrun.

 

[ShaunCorbs]

Easy way to fix the issue is to get a battery prog room stat eg eph cp4b then move the cylinder satisfied wire and pair it with the prog room stat live and diverter switch eg brown

And then marry up all the switch wires eg boiler switch, pump live, cylinder stat call and prog room stat switch live

 

[davidwf]

ah....apologies for not clarifying... the roomstat we have IS a battery powered one

 

[ShaunCorbs]

ah....apologies for not clarifying... the roomstat we have IS a battery powered one

Easy switch over then just moving some wires etc

 

[davidwf]

....which, surely is the setup I have as in #25 ???

 

[ShaunCorbs]

....which, surely is the setup I have as in #25 ???

No as your drawing there’s no connection between the room stat and the boiler unless you’ve miss labelled the pump as the boiler switch live ?

I suspect you’ve got your perm and switch lives mixed up

Eg yellow going to the boiler perm live to the wirings centre and the red coming from the boiler / pump switch live etc

 

[davidwf]

OK thanks, wont know until I can get over to check.....

 

[davidwf]

OK, so I missed out the fused spur supply...... maybe this is how it SHOULD be......

 

[John.g]

Just a quick look but roomstat & cylinder stats are switching the boiler live , they should be switching a SL on the boiler & the boiler should have a permanet Live to allow it to request/do a pump overrun when both the HW & the room stats are both satisfied?.

 

[Basher]

Not sure this is the exact correct model, but likely similar
Mains from the FCU connects to the boiler at one block.
There is a separate connection block to accommodate a live (out) supply to eg thermostat , a switched live (in) from eg thermostat, a neutral etc etc as below simple example.

Ls is live supply (out). Lr is switched live (control in)

So the Boiler L in the diagram above (post #34 yellow and grey wires) should actually be Lr in the boiler. Hopefully it is like that already.

 

[davidwf]

Again thanks for the prompt replies.....I will check I all out when i next go over ......and will of course report back 😁

 

[davidwf]

right.....having gone through all the connections it appears that on the cylinder stat, C & 1 were reversed....the stat is actually marked 1,2,3 rather that C,1,2 which might explain it
I have corrected this and re-drawn the actual installation as it is, I also fitted a new Drayton home battery operated programmable thermostat just to eliminate that
When I tried it yesterday it all seemed OK but was later advised that after the water had been on the rads were still getting hot at the top - suggesting a short run rather than being on all the time
The diverter valve is new and moves and seals OK

 

[Basher]

As far as I can see, the only difference the reversal of C and 1 would make, is that the diverter valve would be permanently powered once the cylinder stat is satisfied, irrespective of whether timer is on or off.
Having corrected the C/1 swap, the diverter is no longer powered once the timer is off.
So I hope residual boiler heat won't now be continually pumped around the rads as before, but it seems there's still something of that effect?

Well done for finding that wiring feature!

 

[davidwf]

yes....but if the diverter valve IS / WAS being held open that would explain the residual heat around the rads whilst the pump was over-running......it is only a small house with small rads
I will do another check in case I have missed something but, with it operating as it should, there's no way the residual heat CAN circulate around the rads is there.......unless the pump pressure is keeping the valve open but that is unlikely
"feature" indeed 🙄