Wiring of recirculating HW pump to Honeywell 10-way junction box

[Archway]

My old system had a recirculating HW pump fitted due to the long run to the kitchen. This was wired to operated only when the timer had the HW on. The system has been upgraded to a Vaillant system boiler & megaflo and the old Grundfos recirculating pump left in place. However, it has been rewired to the Honeywell 10-way junction box (42002116-001) to operate 24/7. This is a bit silly as the water cools while recirculating and after a couple of hours there is just circulating luke warm water.

I want it rewired the way it was but the electrician wont do it - I think because the wiring diagrams available for an S-plan system dont show how to do it.

Does anyone know which terminals to connect the pump to so that it only operates when the timer (Honeywell ST9400) has the HW on? Is there a link to a wiring diagram that I can show the sparky? (I cant find one).

Thanks for any pointers...

 

[Puddle]

Well to put on hot water recirculating pump on timed circuit you could connect the pump live to the same terminal as the hot water switch live from programmer,which also links to the common on the cylinder thermostat
However would not recommend as pump designed to allow short hot water draw off at kitchen tap and will be needed even when hot water side of programmer is off
However it does/can cause unneccessary heat loss from cylinder

I would place pump on its own clock,leave wiring with perminant live and interupt with a mechcanicl clock,the type were pins pull out
then maybe have pump turning off at night and times during day when kitchen sink not normaly used,if needed,over ride can be used
also make sure all curcuit pipework well lagged were posible to cut down on heat loss

 

[birdflue]

Wire the pump through a pipe stat on the return to cylinder the pump will then only run when return loop is cold

 

[Paul Barker]

You have to wonder about the cost of this "comfort". It certainly doesn't sound like the "economy setting ".

Either lag the dhw pipe a lot better or wait for hot water during the day I bet it's cheaper.

As for water saving. The waste heat is harmiong the environment and your pocket more than the cost of water to you or the environment..

But if pump is in same place as 10 position connector centre and cylinder.

Then if you put it into C for hot water either from the cylinder stat or from position 8 (and if your sparks hasn't used Honeywell numbering) brown leed from dhw zone valve, via the afforementioned pipestat the pump will circulate only at times of the day you have predetermined you have a use for DHW and then only when the slug of water in the dhw pipework has shed it's heat.

But I still recon you need to lag your pipes a lot better.

what a perculiar forum system.

Prefer forum 's where editing isn't shown unless someone else has posted on a topic.

 

[Archway]

Well to put on hot water recirculating pump on timed circuit you could connect the pump live to the same terminal as the hot water switch live from programmer,which also links to the common on the cylinder thermostat

Thanks folks - this is what I thought was needed and I just did the job successfully. I appreciate there are more elegant solutions but more lagging means floorboards and wall panels being removed and its a 20+ metre run to the kitchen so I aint just waiting!