CH Thermostat issues

[AndyPRK]

I think it's rather obvious that they have used the green/yellow as a live conductor, but the person wiring that stat didn't know!
You can't make that sort of assumption though. You need to find the wiring center or the other end of that cable to prove it

 

[RF Lighting]

The regulation The English has been questioned, I would say the full stop means it applies to all cables, but some seem to think if a multi-core you can over-mark. However I have pointed out not wired is a professional manor so you have to expect faults and anomalies where some one has not followed convention.

The regulation I’m referring to is 411.3.1.1: “a circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a lampholder having no exposed-conductive-parts and suspended from such a point”

 

[CBW]

The regulation I’m referring to is 411.3.1.1: “a circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a lampholder having no exposed-conductive-parts and suspended from such a point”

So even if no cpc/earth is required on a double insulated thermostat, one still has to be provided? I fit a lot of Siemens RDH100’s, where no earth is required, nor is there a terminal for it. Granted it comes from the boiler feed, which does have a cpc.

 

[RF Lighting]

So even if no cpc/earth is required on a double insulated thermostat, one still has to be provided? I fit a lot of Siemens RDH100’s, where no earth is required, nor is there a terminal for it. Granted it comes from the boiler feed, which does have a cpc.

Yes whether it is required or not it must still be provided.

 

[CBW]

Yes whether it is required or not it must still be provided.

Thank you. Would I just need it in a choc block, wago, or Do I just provide the wire?

 

[Adam_151]

It needs to be suitably terminated, so either a connector block or a wago is fine, or I suppose crimping it in one end of a through crimp. A lot of house bashers will simply use a longer than necessary piece of earth sleeving (when wiring in cables with a bare cpc) and bend it over, but that isn't really a practice to be encouraged!

 

[CBW]

Thanks. I was told by a spark who I work with as I usually use 5 core flex to just provide the wire both ends so it can be tested? This is what ive been doing thus far.

 

[ericmark]

So even if no cpc/earth is required on a double insulated thermostat, one still has to be provided? I fit a lot of Siemens RDH100’s, where no earth is required, nor is there a terminal for it. Granted it comes from the boiler feed, which does have a cpc.

The rules changed in 1966, up to then you did not need to run an earth to light fittings. Now only pendent is allowed without an earth. Where there are multi-cables then only one of the cables would need to carry an earth, however personally I think using any green/yellow cable for other than earth is asking for problems.

 

[jimmybobfixer]

What we need to do is work out what was in the mind of the guy who wired it.

.

ok lol

The "Faulty" stat makes the motorized valve open permanently and request heat. Downstairs under floor heating does not seem to request heat from the boiler, so only works if the water is hot or the upstairs is requesting the boiler to heat up. (strange be cause the underfloor heating has a separate junction box and there is a space for wiring to the boiler, but its missing lol)

if there is no request for heat upstairs from the room stats then the under floor heating does not seem to heat up downstairs.

 

[jimmybobfixer]

I think it's rather obvious that they have used the green/yellow as a live conductor, but the person wiring that stat didn't know!
You can't make that sort of assumption though. You need to find the wiring center or the other end of that cable to prove it

that was my first thought, and did attempt to look at wiring center. However it looks like sh!t in the wiring center. Ill post a pick maybe i am being too critical lol

THe wiring for the stat in question has probably got a join in the attic somewhere.

 

[ericmark]

Repeat.

 

[ericmark]

Under floor heating normally has a second circulating pump and a load of valves the wiring centres are rather special and the pump and valves are really independent of the main central heating what it does is maintain water at 29°C by adding more hot water as the circulating water cools, however there are other methods, you say 4 motorised valves, and I wonder why so many, one for domestic hot water and three for central heating seems a little OTT, so wonder if your talking about an actuator looks like a TRV with wires to it. They are I supposed motorised valves so are programmable TRV heads, but we don't tend to think of them as motorised valves, this

is typical with under floor heating, but also seen so cheap methods, one is to use the return from the radiator to heat under floor, so in that 4 motorised valve count how much is for UFH?

 

[jimmybobfixer]

Under floor heating normally has a second circulating pump and a load of valves the wiring centres are rather special and the pump and valves are really independent of the main central heating what it does is maintain water at 29°C by adding more hot water as the circulating water cools, is typical with under floor heating, but also seen so cheap methods, one is to use the return from the radiator to heat under floor, so in that 4 motorised valve count how much is for UFH?

ill get a photo of the underfloor heating. there is a motorised valve for that

there are 4 motorised valves upstairs (one for each radiator in bedrooms) one also upstairs for indirect? cylinder. There is a 1 motorized valve downstairs for the underfloor heating.

 

[jimmybobfixer]

under floor heating

20201031_102705

• jimmybobfixer
• 31 Oct 2020

wiring for bedroom room stats and motorized valves

20201031_102758

• jimmybobfixer
• 31 Oct 2020

motorized valves for bedroom heating

20201031_102806

• jimmybobfixer
• 31 Oct 2020

 

[ericmark]

Working on that will be no easy task, I was going to say not a DIY job, but only the DIY man likely has the time to work out what it all does.