Boiler/ timer pump wiring

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Just replacing my old boiler. The pump in the airing cupboard was switched directly by the water / heating timer in the kitchen.

The new boiler has the pump switched by the electronics control inside the boiler itself. To save running a wire up the outside wall into & across the loft, then down into to airing cupboard to the pump, could I disconnect the pump wire from behind the water / heating timer, & extend & route it (~1 ft [sorry E.U, 300mm]) to the boiler?

My main reason for asking is I’ve opened the junction box in the airing cupboard & see the pump wire also goes to a couple of wires inside the 3 way valve, as I’m not a heating engineer I was just concerned.

Thanks for any advice.

Mark (electronics engineer)
 
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I'm not sure many guys on here will advise DIY'ers when they're doing work that's meant to be done by gas qualified engineers.

Best thing I could say is to get someone in that knows or at least follow the instrucions that the boiler came with. It's not a Ravenheat by any chance is it?
 
Just replacing my old boiler. The pump in the airing cupboard was switched directly by the water / heating timer in the kitchen.
...

I’ve opened the junction box in the airing cupboard & see the pump wire also goes to a couple of wires inside the 3 way valve

Make and model of three way valve?

Which valve wires do the pump wires (brown, blue, green-yellow) connect to?

To save running a wire up the outside wall into & across the loft, then down into to airing cupboard to the pump, could I disconnect the pump wire from behind the water / heating timer, & extend & route it (~1 ft [sorry E.U, 300mm]) to the boiler?
This should be possible, but we need to know which boiler you are having installed and the three way valve info.
 
The boiler is a Potterton Suprima. Regular boiler, that just has connection for:
1. mains input
2. a switched input (from the timer)
3. The pump output
So it’s a pretty basic system

(I’ll be calling the Gassafe guy when I’m ready for the gas connection, certainly not before)

Make and model of three way valve?
Sundial Y plan 3 position diverter valve.


Which valve wires do the pump wires (brown, blue, green-yellow) connect to?

Blue: to one of the valve motor wires
Orange: to one of the two micro-switches
White: to micro-switch (can’t see which one)
Grey: to micro-switch (can’t see which one)
(Gn/ylw earth)

In the junction box the pump Live connects to the Orange wire (above) & also to a wire that goes to the tank thermostat.

I assume when the tank water temperature is achieved the thermostat opens the contacts to dsables the pump. If I can find a ‘standard’ wiring schematic for a regular water / heating system I can confirm things. The house is ~25 years old now if that’s of any use.

Mark.
 
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This diagram shows a y plan diagram for pumps with a boiler controlled overrun like yours.

http://octaveblue.co.uk/c_heating/hw1_ch1.htm

In the junction box the pump Live connects to the Orange wire (above) & also to a wire that goes to the tank thermostat
Disconnect the pump live wire from here (in wiring centre) and connect to the '3. pump output' connection on the boiler.

Next, connect the '2. switched input (from the timer)' on the boiler to the connection on the wiring centre where you have just removed the pump live wire from.

Don't confuse the issue by worrying about microswitches, this will only complicate things.

Whatever you do, get your Gassafe to check your wiring before switching on the juice!!!
 
Thanks whitespirit66, the diagram made clear what's what & answers my question in that I will need to run a new wire from the boiler to
the pump & can not simply terminate & re-use the wire from the timer.

As a component level test & repair engineer the micro switches would complete the picture, there's nothing worse than a box with wires coming out & not knowing EXACTLY what is inside, but problem solved so case closed.

Thanks again.

Mark.
wallisonwheels.com
 
hope you never installed the flue any gas pipe work etc. you may find it hard to get someone to sign a boiler off that has been put on the wall by a regular human. especially a regular boiler! :LOL:
 

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