hot water circulating pump "off-delay" relay switc

[steveuk1971]

THIS QUERY DOES RELATE TO ELECTRICS AND NOT PLUMBING SIDE OF THINGS.

Here is brief rundown of my situation.

My problem is that the central heating circulating pump in the airing cupboard is connected directly to a switched-live connection and as soon as the switched-live connection (triggered by the room and/or hot water cylinder thermostats) is broken the pump goes off straight away.

what I need is for the pump to still run for 60 seconds after the switched live connection has been broken hence the need for a 60 second off-delay 240 volt relay switch.

Is there such a switch/relay out there available to fit??

Thanks so much.

Steve.

 

[didthathurt]

what I need is for the pump to still run for 60 seconds after the switched live connection has been broken

Why?

 

[steveuk1971]

what I need is for the pump to still run for 60 seconds after the switched live connection has been broken

Why?

because if the pump goes off immediately the switched-live connection is broken then there is heat build up in the boiler heat exchanger causing kettling/rumbling noises in the pipework. The 60 second delay would allow the pump to pump the water for 60 seconds after the boiler has gone off.

I did have a pump-over-run circuit on the boiler itself, but this integral boiler switch/relay/overrun is broken and to save money on a whole new boiler PCB I want to fit what is effectively an external pump over-run circuit.

Thanks.

 

[breezer]

this ok?

just found this may need an aditional relay if load over 200w

 

[toasty]

The other (better) option would be a pipe thermostat attached to the pipe feeding the pump, use it to provide a live feed to the pump if the water is over a certain temperature.

That way the pump will run on until the water drops to a low enough temperature.

-Dan

 

[Lectrician]

CLICKY

 

[steveuk1971]

The other (better) option would be a pipe thermostat attached to the pipe feeding the pump, use it to provide a live feed to the pump if the water is over a certain temperature.

That way the pump will run on until the water drops to a low enough temperature.

-Dan

That sounds good. Where would I get a pipe thermostat as suggested - a normal plumbers merchant or could you provide a link to one online?

Is it easy to fit to the pipe - I can do basic electrics ok.

Many thanks.

Steve

 

[steveuk1971]

CLICKY

Hi, the link did not work due to session time out. Can you redo the link?

Thanks.

 

[toasty]

Yep,

It just clamps to the pipe.

Wire it like a normal switch with common L1 and L2 etc....

Here's one - http://www.plumbworld.co.uk/0-2964

 

[steveuk1971]

The other (better) option would be a pipe thermostat attached to the pipe feeding the pump, use it to provide a live feed to the pump if the water is over a certain temperature.

That way the pump will run on until the water drops to a low enough temperature.

-Dan

actually when the pipes are cold in the morning, how would the pump turn on when the boiler starts? would the pump not start until the pipe got hot?

 

[toasty]

No,

The bolier would still activate the pump as usual, just wire the pipe stat in to also provide a live to it when the water is hot.

 

[steveuk1971]

No,

The bolier would still activate the pump as usual, just wire the pipe stat in to also provide a live to it when the water is hot.

Great

 

[steveuk1971]

No,

The bolier would still activate the pump as usual, just wire the pipe stat in to also provide a live to it when the water is hot.

Just tried to run that through on a wiring diagram but unsure as to one part. the pump has 3 wires, earth, neutral and live. i understand how to fix and wire the pipe stat so that when the pipe is hot it closes the switch and live elec wire connects to the pump so pump runs until pipe stat is cool enough.

but is the pump live also connect to the boiler live which has the programmer/stat link in it? hence if pipe stat live is connected then will it not also be sending live to the boiler?

Sorry to be confused? Maybe you could PM me and email me direct a diagram if unable to post it on here?

Many many thanks.

 

[steveuk1971]

this ok?

just found this may need an aditional relay if load over 200w

hi. is the second item an off delay timer?

 

[moderator]

[quote="steveuk1971 Maybe you could PM me and email me direct a diagram if unable to post it on here?[/quote]

How is any one going to PM you? there is no PM facility on this forum. You may show your email address in your profile