Wet Under Floor Heating Modification

[Delectrician]

Hi Guys.

I have a flat with a 9KW electric boiler, dedicated for the wet underfloor heating system. The tenants have reported that all the digital room stats were not working, as when they increased the temperature to get more heat, nothing was happening. Within 15 minutes in the property I discovered that all the room stat controls were disconnected at the central chalk block terminals, There is a 1.5mm2 T&E cable running to each digital room stat from the main terminals, then the stats run on batteries, I'm thinking the T&E cables are simply carrying control voltages, although not entirely sure. I then noticed all the motorised valves had been disconnected from the flow & return manifolds, Further more the pump has been wired so its constantly running, when the 45A main isolator is on. Someone has basically just completely simplified the system, in a rather cowboy fashion.
Now I've suggested 2 ways forward to the landlord...

1. Re-instate the motorised valves & replace faulty room stats (battery leak on x2 stats) & correct the wiring, so the pump only runs when the system is putting out heat.

2. re-configure the central wiring & fit a Sallus wireless thermostatic time clock system, so the whole flat is operated from the one wirelessly operated thermostatic time clock.

My concern is wit the 1st option, I require a plumber to re-instate the valves & I know the landlord will be doing a refurb on this property as soon as its vacant, so he is very unlikely to go for a fix that costs upwards of £600, which I'm sure will happen here.

I think number 2 is the way forward, what I want to know with this is, do I need to take a 3-core from the PCB in the electric boiler to pick up the thermostatic control circuit, or can I just use the wireless thermostatic timeclock in a simply on off fashion, via the main switched live for the boiler.

Any insights, or help massively appreciated..

Thanks

Derek

 

[Pete999]

If the best and safest way to repair this mess, and it requires the input and helpof a Plumber, then so be it Derek.

 

[davesparks]

Have normal motorised valves been used? These systems normally use thermal actuators fitted onto the manifold.

Fitting a single thermostat to control all zones is not a sensible option unless you have the means of properly balancing the zones on the hydraulic side.

 

[DefyG]

Fitting a single thermostat to control all zones is not a sensible option unless you have the means of properly balancing the zones on the hydraulic side.

Which you might need a plumber for in any case.
These systems are designed around sing zonal room thermostats for optimum efficiency so best revert back to it ….. Option 1