Changing Danfloss TP-One thermostat with Hive dual system [Hot Water & Heating]- HELP please

[jimderosa]

Hi,

i am currently running a LOGIC 18 boiler with water tank in the airing cupboard in a new build. My thermostat is a TP-One Danfloss and i am looking to replace this with Hive. I am happy to replace the current thermostat [which controls hot water & heating] which is located in my hallway with the Hive receiver.
I have read lots of threads on here but come across an issue with the wiring. [photos attached of current TP-One wiring]. The issue i have is i have an extra wire going into port NC2 which i cannot for the love of money find any information about other than it means "normally closed".

Existing TP-One Thermostat Wiring:

I went ahead with changing the wires as people suggested on here and this is what i did:

Moved the wires to the following:
Danfoss N = Hive N
Danfoss L = Hive L
Danfoss NO1 = Hive Heating on 4 (also marked NO)
Danfoss NO2 = Hive Hot Water on 3 (also marked NO)

Hive Receiver wired following advice on this forum and following the above:

As i couldn't find any information on NC2 so i just left this one disconnected. Once i fired it all up, i got the solid green light on the receiver but when i checked the boiler it was showing fault FD.
I am guessing this has something to do with the wire which was located in the TP-One NC2 port.

Can anyone help me please and point me in the right direction??
Appreciate anyones help, Thanks!

 

[CountryFan]

Do you have a Y plan system (one motorised valve that does CH/HW/Both)? If yes, it would be needed for hot water off. A quick search states an FD is water not flowing.

 

[RandomGrinch]

As above, NC2 is hot water off on the Danfoss.
Move the grey wire to terminal 1 of the Hive backplate.

 

[jimderosa]

Do you have a Y plan system (one motorised valve that does CH/HW/Both)? If yes, it would be needed for hot water off.

I am told it is an S plan but not 100% sure myself. I have one thermostat in the hallway which controls hot water and heating to every room apart from the master bedroom and master ensuite.
I then have another Tp one thermostat controller in the master bedroom which controls heating only for the master bedroom and ensuite.
This is running off a battery and not mains but does have 2 cables running into the back of it.
This is the back of the TP one in master bedroom:

Thanks

 

[CountryFan]

Ok, can you post a photo of the cylinder cupboard, if you have one?

 

[jimderosa]

Ok, can you post a photo of the cylinder cupboard, if you have one?

 

[CountryFan]

View attachment 364127

Could be an s plan plus. You have another valve just out of shot above the other 2, can you take another one of that? Sorry, just trying to ascertain that NC.

 

[jimderosa]

Could be an s plan plus. You have another valve just out of shot above the other 2, can you take another one of that? Sorry, just trying to ascertain that NC.

 

[CountryFan]

I’m a little stumped then as you appear to have an s plan plus, but a normally closed connection, which is used on a y plan system. Try connecting it to the hot water off and see if it works.

 

[jimderosa]

I’m a little stumped then as you appear to have an s plan plus, but a normally closed connection, which is used on a y plan system. Try connecting it to the hot water off and see if it works.

Will this do any damage to the boiler if its wrong? Thanks

 

[RandomGrinch]

Will this do any damage to the boiler if its wrong? Thanks

No, because that's exactly what the Danfoss was doing.
...it still doesn't mean that the grey wire is connected to anything at the other end! The problem could be completely coincidental.

 

[RandomGrinch]

I’m a little stumped then as you appear to have an s plan plus, but a normally closed connection, which is used on a y plan system. Try connecting it to the hot water off and see if it works.

It took me a while, and the search led back to....

Nest/Boiler issues

your wiring diagram is wrong, shouldnt be anything in SL2 and the Outside sensor is wired into the terminal on the RHS installer panel marked weather compensation page 36 of the manual, HW off and HW satisfied are not used...

www.diynot.com

The H/W off connection is used for weather compensation, on these specific new build set ups.