Wiring grant vortex (pump overrun)

Kealyboy · 27-10-2025 08:04PM #1

Hi,
Im just wondering is there anything that can be done with the wiring of grant vortex boiler house model wiring.
in the house (kitchen) there is a old apt time clock and the out in the garage (boiler house) existing boiler has just a LNE. When pluming in the grant is there anything that can be done with the wiring so the grant vortex can have a pump overrun. Heating system is not zoned or anything. As I said just a old APT time clock in the kitchen and LNE supply in garage.

Thank you

Lenar3556 · 27-10-2025 08:35PM

There would be several options, ultimately you need a permanent live to the pump, which will be controlled by either a pipe stat or overrun timer.

You could make the cable to the boiler a permanent supply which would power the pump via a pipe stat set for about 45 degrees mounted on the flow connection of the boiler. The signal to start the boiler would then need to be wireless (switching this same permanent live supply), either using a room stat and relay arrangement like the EPH one below;

https://www.plumbingproducts.ie/wireless-thermostats-ireland/5602-eph-combipack4-programmable-rf-thermostat.html

Or for longer distances and perhaps more reliable signalling, something like the below. Scantronic also do a particularly good equivalent 12v system.

https://www.rfsolutions.co.uk/remote-control-systems/mainslink-remote-control-systems/

Kealyboy · 27-10-2025 08:36PM

Could I use a pipe stat? and wire the pump through the stat. Attach the stat on the flow pipe closest to the boiler as possible would this work

Kealyboy · 27-10-2025 08:46PM

I just sent that last reply just as you sent yours. Yea I like the pipe stat option.

If I was to wire the boiler without a pump overrun would this be ok. I presume the heat exchanger is cast iron.
My parent have a old firebird popular 90 wired with no pump overrun and boiler is still running fine 30 years old

Kealyboy · 27-10-2025 08:48PM

https://www.boards.ie/discussion/comment/123942377#Comment_123942377

thank you very much for your reply very informative

Lenar3556 · 27-10-2025 09:23PM

https://www.boards.ie/discussion/comment/123942391#Comment_123942391

Most domestic boilers have no pump overrun and they perform fine without, particularly if the boiler thermostat is set modestly.

Particularly given that the system is unzoned, I wouldn’t worry about a pump overrun, unless you were experiencing particular issues.

Vortex and most condensing boilers have a stainless steel heat exchanger.

Kealyboy · 27-10-2025 09:47PM

https://www.boards.ie/discussion/comment/123942464#Comment_123942464

yea I think I will install without the pump overrun for the moment and if issues occur I will install after.
I should be ok though, I’m just afraid I’ll damage the boiler. You reckon it would be ok? That stainless heat exchanger won’t be damaged as a result.

declan b · 28-10-2025 09:30PM

You dont need a pump overrun

Kealyboy · 29-10-2025 09:30PM

another question, I had to break out hole for low level balanced flue under existing hole. Should I sleeve flue with some 4 inch wavin pipe before filling it with cement . Or can I just fill it as it is… once boiler is fitted

IMG_4534.png

See pic attached.

Lenar3556 · 29-10-2025 09:54PM

https://www.boards.ie/discussion/comment/123947305#Comment_123947305

It doesn’t need to be sleeved, and to do so might introduce a pathway for flue gasses to be blown back into the building. Sand and cement is best.

Incidentally it wouldn’t fit in a 4” pipe, the outer diameter of the Grant yellow balanced flue is about 125mm

Kealyboy · 29-10-2025 10:07PM

https://www.boards.ie/discussion/comment/123947397#Comment_123947397

Ok just sand and cement it is. That has made life a little bit easier for me. I would of been there for quite a while trying to fit a 4 inch wavin soil pipe around that flue 😂 (in my defence I hadn’t put that much though into it) 😬 thank you

Wiring grant vortex (pump overrun)

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