R
ringy1
Can anyone please tell me why does the vokera mynute 25 A boiler need a relay board fitted when wiring??? And what exactly does the relay board do???
Thanks Guys
Thanks Guys
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I would have expected that boiler would accept 230 v call for heat signals.
Some modern boilers need low voltage isolated two wire circuits and if a system has a 230v controls then a relay is required to isolate the 230v from the boiler.
But without reading the boiler instructions I cannot give you definitive advice. Can you offer me a link to that requirement?
Tony
Some modern boilers need low voltage isolated two wire circuits and if a system has a 230v controls then a relay is required to isolate the 230v from the boiler.
But without reading the boiler instructions I cannot give you definitive advice. Can you offer me a link to that requirement?
Tony
R
ringy1
I'm living in Ireland now and just moved into a new house. I've upgraded my gas boiler to a Vokera mynute 25 A. Now the plumber could not wire the boiler so I called a spark and when he wired the boiler he blew the PCB. After I called a gas service guy he said that boiler was a low voltage contact and that he needed to wire the switch live from the external controls to a 230v ac- dc relay board and then back to the PCB.
I'm just trying to understand it all a bit more
I'm just trying to understand it all a bit more
I have read the makers instructions and they confirm that the boiler requires low voltage control inputs.
Usually, when fitting a new boiler, a programmable thermostat would be fitted and they have low voltage volt free contacts.
If you must still use controls operating at 230v then a relay is required to isolate them from the boiler. But most would advise using low voltage controls but it all depends on what you have now.
Now the interesting bit ! When the electrician wrongly wired the controls and blew the PCB then who paid for the replacement which was probably about £150 ???
Tony
Usually, when fitting a new boiler, a programmable thermostat would be fitted and they have low voltage volt free contacts.
If you must still use controls operating at 230v then a relay is required to isolate them from the boiler. But most would advise using low voltage controls but it all depends on what you have now.
Now the interesting bit ! When the electrician wrongly wired the controls and blew the PCB then who paid for the replacement which was probably about £150 ???
Tony
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R
ringy1
Oh right that make sense now so the relay steps down the voltage from 230v to lower voltage is all and converts it to dc. The relay cost me €60 to buy and then a further €80 to install. I then heard they can be bought from a electrical suppliers for €12 oops. If I was to of bought one from a electrical supplier what exactly would I of being asking for? Cause I want to get a price for one now to see was I robbed.
And to answer your question the spark paid for it which was fair enough
And to answer your question the spark paid for it which was fair enough
A suitable relay costs about £5-£10 as a plug in and a base to suit about £5 with wire terminals.
Maplins have them. There are several types and pretty well anything will work.
The relay only provides contacts which are closed when the relay is powered. It does not provide or convert any voltages.
Tony
Maplins have them. There are several types and pretty well anything will work.
The relay only provides contacts which are closed when the relay is powered. It does not provide or convert any voltages.
Tony
R
ringy1
Ok it's all getting clear now but if there is 230v supplied to the relay and then the contacts close when powered and then you have your two wires connected from C and NO to the PCB, what stops 230v being supplied through the relay to the PCB thus blowing the PCB? How does the relay protect the PCB?
There is no connection between the 230v and the contacts.
Its just a switch operated by the 230v on a coil.
The contacts can be used for anything and are completely isolated from the 230v supply.
They are the old fashioned way to do this. Nowadays its done by optoisolators but they are too new for boiler people to use ( or rather they dont understand them! ).
Tony
Its just a switch operated by the 230v on a coil.
The contacts can be used for anything and are completely isolated from the 230v supply.
They are the old fashioned way to do this. Nowadays its done by optoisolators but they are too new for boiler people to use ( or rather they dont understand them! ).
Tony
Ringy1, I think your boiler is a Minute EHE, I could not find a Minute A. There also is a 25HE model, so indicating which one you have will make assist in giving correct advice.
Your boiler is a system boiler, so it will heat radiators and also water in a cylinder. Therefore, if your guy fitted two motorised valves, (one for HW and one for CH), there is no need for a relay board or a relay. On the other hand, if a Y plan has been fitted, then a means of telling the boiler to get working with 240 volts will be needed. A relay is not the only way to do this by the way!!
If motorised valves have not been fitted, it would be prudent and economical to do so.
Your boiler is a system boiler, so it will heat radiators and also water in a cylinder. Therefore, if your guy fitted two motorised valves, (one for HW and one for CH), there is no need for a relay board or a relay. On the other hand, if a Y plan has been fitted, then a means of telling the boiler to get working with 240 volts will be needed. A relay is not the only way to do this by the way!!
If motorised valves have not been fitted, it would be prudent and economical to do so.
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