Underfloor heating pump wiring

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this is the setup its really simple one no valves nothing, i am just curious how to get this circulating manifold pump to get power from the boiler so that it turns on same time with the boiler when the heating is turned on? is it possible to wire it to boiler pcb somehow ? this is the pcb of the boiler if that helps
 
the radiator water temperature is set at 70 degrees, since radiators and UFH runs on the same loop I just use the temperature regulating valve just below the manifold pump to keep UFH temperature lover temps, just can figure out how to switch the manifold pump automatically when they boiler is in heating mode
 
sorry uploading images again
 

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Madrab said:
@zig122 if I remember rightly (would need to check the manual) there is a switched live option for the logic + combi that allows a live to be take from the boiler and run through the stat and back to the stat terminal on the board. If so then that setup could probably be utilised to provide a switched live out to the pump.
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Unfortunately it's not as simple as it seems, otherwise everyone would be doing it ;)

Again ..... How do you switch the CH on just now? Is it just using a timer on the boiler? You can't just take the power from the pump feed in the boiler as that will activate the pump when HW is used too. If you check you boiler manual, you want to find the section headed external electrical controls. That tells you what you need to know.

You will need to fit a thermostat (relay), as suggested earlier, to control the heating and that will allow a live feed to be sent (relayed) to the pump when the stat (CH) is calling for heat.

Madrab said:
Unless your GSR'd tho then you shouldn't really be in the (room sealed) case playing around. That and unless you know your way around the electrical systems in a boiler and are handy with a voltmeter and know what to check, then you may want someone that does in to wire it up otherwise the PCB could be fried.
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To be clear that is exactly what a remote power switch does....you take a pump pwr live feed from the boiler pcb and pop it into a remote switch, ...when the CH pump starts the UF pump starts. I am not sure how much simpler it can get...unscrew pwr live on pcb add wire screw up, do same to remote switch and add a power feed , at the pump end cut the pump feed three core and wire up the two ends into the receiver switch ....If your boiler has over run use an over run model....

As for a bit of pump run when hot water is called for so ? at the moment he is running upstairs to turn on and off the pump manually...30 minutes of extra pump run...if his boiler does actually over run on HW is going to cost him what in comparison to leaving it on all the time ??????

Mind you having just looked at the circuit diagram he could just trigger the remote pump by using the CH SWL connector on the wiring diagram...I mean its only been placed there for that very purpose.....
 
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martygturner said:
To be clear that is exactly what a remote power switch does....you take a pump pwr live feed from the boiler pcb and pop it into a remote switch, ...when the CH pump starts the UF pump starts. I am not sure how much simpler it can get...unscrew pwr live on pcb add wire screw up, do same to remote switch and add a power feed , at the pump end cut the pump feed three core and wire up the two ends into the receiver switch ....If your boiler has over run use an over run model....

As for a bit of pump run when hot water is called for so ? at the moment he is running upstairs to turn on and off the pump manually...30 minutes of extra pump run...if his boiler does actually over run on HW is going to cost him what in comparison to leaving it on all the time ??????

Mind you having just looked at the circuit diagram he could just trigger the remote pump by using the CH SWL connector on the wiring diagram...I mean its only been placed there for that very purpose.....
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Is that reply to me or the OP, not sure?
 
Both of you I suppose...its just there is a lot of over thinking going on... He said his installation was fine but he needed to manually turn the pump on which he wanted to fix....well that's pretty simple doesn't need to worry about temp as its sorted by his temp regulator or worry about manifold switching or diverter vales or anything else.

As I said the wiring diagram shows him the CHSWL output to use to use if he wants if he wants the remote pump to just come on with the CH or he can just have the pump on when the boiler fires ...no great shakes is it....its there on the diagram why not just tell him ??? why allude to it.

Then just give him the solution either hardware a connection up or bang in a remote switch..... which is the easiest as he has all that is needed bar the switch and a lump of twin and earth.

Heating is only difficult when we make it so.
 
Well thanks for that. IMO I wasn't making it difficult nor over thinking it. Have been doing these systems for a long time, UFH shouldn't just be left to do it's own thing, it needs the simplest of room temp control at least, hence the stat.

He needs to control his pump feed from the connector block, no where near the PCB, the easiest way to do that is to use the thermostat that can also be used as the switch for the pump. That can all be fed from a bridged live from the boiler choc block, it's in the manual, bottom left

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The UFH shouldn't be left pumping against the boiler's DV when it's in HW mode, especially if say in a shower for 10-15mins, won't do the valve nor the pump any favours, unless there's an external bypass fitted.
 
Again ...look at the wiring diagram and his picture...the brown choc box at the bottom has a black CH SWL coming to it...use that ...it gives voltage when the ch fires...we don't need 240 volts any voltage will do just enough to trip the remote switch but in this case it is 240v...its the top empty ones..CHSWL ...upstairs we can use 240v to switch on the pump.

Second he is switching the pump on manually at the moment....think about it...I know I have..so that pump is running all the time even when the HOT Water is being used I mean nobody ever has a shower when the CH is on, do some washing up ????.....so what pray would be the difference. either way the boiler diverter shuts.
 
No need for any wireless remote switches or anything like that, just needs a £15 240v stat and the cable, that and the UFH/rad system should have a thermostat anyway and that can be used to send 240V straight to the pump, seems to me to be the simplest solution, hardest part is the cable routing. Also, in my experience it's always best to use the manufacturers suggested options rather than making up them up, especially if it comes to warranties etc but that's just splitting hairs, either way could supply the stat with 240v.

Whether the pump is being manually switched on or not and running when in HW mode is immaterial IMO, no pump should be running against any closed head hence the need for autobypasses, it's not good for the pump nor the Div valve in the case of a combi. So the best serviceable option here would be to fit an autobypass, again as suggested in the MI.

Ultimately though it's up to the OP.
 
Madrab said:
Well thanks for that. IMO I wasn't making it difficult nor over thinking it. Have been doing these systems for a long time, UFH shouldn't just be left to do it's own thing, it needs the simplest of room temp control at least, hence the stat.

He needs to control his pump feed from the connector block, no where near the PCB, the easiest way to do that is to use the thermostat that can also be used as the switch for the pump. That can all be fed from a bridged live from the boiler choc block, it's in the manual, bottom left

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The UFH shouldn't be left pumping against the boiler's DV when it's in HW mode, especially if say in a shower for 10-15mins, won't do the valve nor the pump any favours, unless there's an external bypass fitted.
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Sorry for long replay was very busy, i tried to connect the pump to thermostat and all the terminals on the boiler when you open it up like in your pictures but it could power the pump, and the thermostat seems to be low voltage as well maby i am wrong.

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My finger is on thermostat wire and wire next to it is mains comingto to boiler maby someone knows how to connect those two UFH pump wires here so that it runs when thermostat calls for heating
 
Your stat is using the switched live (SL) side of the wiring to switch it on and off, I presume there is a mechanical clock in the front of the boiler to control the time? So in my pic, post #24, section 33, Right hand side is where you stat is wired to just now, which is a 240V switched live.

Do you want to control the pump like the boiler from the thermostat? If so then you'll need to run a neutral and earth from the boiler, or FCU and then take a live from the switching side of the thermostat, usually terminal 3.

Just need to get handy with a voltmeter and check that terminal 3 on the stat is the switched side. When the stat calls for heat it will turn on the boiler and send a switched live to the pump.

I'm sure the SL for the stat should be able to handle to load for the pump, though I'm sure someone here will be able to confirm you can load a pump onto that side of things on the Logic. @ianmcd @DP

Do be careful though, if you're not sure what you're doing then don't as you could cause yourself and the boiler major injury!!
 
Madrab said:
Your stat is using the switched live (SL) side of the wiring to switch it on and off, I presume there is a mechanical clock in the front of the boiler to control the time? So in my pic, post #24, section 33, Right hand side is where you stat is wired to just now, which is a 240V switched live.

Do you want to control the pump like the boiler from the thermostat? If so then you'll need to run a neutral and earth from the boiler, or FCU and then take a live from the switching side of the thermostat, usually terminal 3.

Just need to get handy with a voltmeter and check that terminal 3 on the stat is the switched side. When the stat calls for heat it will turn on the boiler and send a switched live to the pump.

I'm sure the SL for the stat should be able to handle to load for the pump, though I'm sure someone here will be able to confirm you can load a pump onto that side of things on the Logic. @ianmcd @DP

Do be careful though, if you're not sure what you're doing then don't as you could cause yourself and the boiler major injury!!
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Thank you i will try to do what you said, hopefully it will work, thanks for your time
 
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