Help with wiring the hot water controler



  • Thanks. I was in gravity setting but still not working in fully pumped. The pump is not coming on when the heat is called for by the radiators, but does when called for by the hot water.

    I’ve included pictures of the pipes that heat up when pump for hot water comes on and a picture of the wiring of the programmer just in case I’ve got something wrong.
  • Pics didn't upload. Here they are again

  • The wiring looks okay. I assume you bridged the brown and yellow wires from the old thermostat?

    I'm wondering if your heating depends on whether the HW cylinder thermostat is calling for heat. With the Receiver configuration set to Y-Plan can you try 3 different tests.

    1) Hot Water only. Turn the cylinder thermostat up and down to check the boiler turns on and off, and check the appropriate section of pipe gets hot.

    2) Radiators only. Turn the room thermostat up and down to check the boiler turns on and off, and check the appropriate section of pipe gets hot.

    3) Radiators and Hot Water together. Turn both thermostats to their maximum to check the boiler turns on, and check the both sections of pipe get hot.

    You will need to be patient when performing these tests. Tado can take a minute to respond to each input and the boiler will also take time to respond.

  • Yes, brown and yellow wires have been bridged and blue capes off.

    Before installing Tado my heating would work independently of hot water.

    On your 3 tests:
    1) pump turns on and off if I turn the cylinder thermostat up and down

    2) pipes do not get hot and pump doesn’t turn on or off when radiator and wireless thermostat are cranked up

    3) radiators do not turn on when when both hot water and heat are turned on.
  • Some clarification needed. For option 3 did the pump/boiler turn on? Hot water side of the valve heats up.

  • Pump didn't turn on and pipe to left of the diverter did not really heat up either. I'll go up now and see if I can use the manual overide switch on the diverter to see if I can get the radiators to warm up.

  • The manual overide did get the pump to kick in on heating mode and the radiators are starting to heat up to trvs seem to be working.

  • And should have said, diverter valve switch seems to have three settings. Auto, both heating and hot water, or manual overide which seems to prioritise heading.

  • I'm at a loss to explain what is happening. Electrically HW only and HW+CH are the same, the difference is the motor moves the diverter to a different position. I would expect the pump/boiler to operate for both of these modes

    Electrically CH only is different as a switch inside the valve is activated in this position. As you've found out the lever will manually move the diverter to the CH only position, which the activates the switch.

    I think you're going to need an electrician to check the voltage on the wireless receiver terminals and to verify the motor on the 3-port valve is working.

  • Hmm, I going to take a look at the wiring again today. I did think the other day that the HW and CH were working together (when in gravity / blue dot mode) but it didn't seem to work like that yesterday in pumped / green dot mode.

    I'm sure there must be something going wrong with the wiring.

    Is it easy to test the voltage? Which terminals need testing? I now have an eletrical tester tool of my own. I used it to test continuity in the salus box as you suggested the other day when checking the wiring of the wired thermostate cables in the hall. All show no continuity / open loop. If it's straight forward I could try it myself and see if that tells us anything more.

  • Your comment abount no continuity on the hall thermostat could be the problem here, there should be continuity between the brown and yellow/green wires of the hall thermostat. Can you confirm if that is the case? Any live testing sould really be done by an electrician

  • Hi starconf, the continuity testing done previously was to check there was no was no continuity between the earth terminals and terminal 2. Not live testing of continuity. What terminals would need to be tested to check continuity was correct?

    For info the motorised valve terminals of the system has been live tested. The readings are below. What is this telling us?

  • Also, if it helps i've traced all the wires in the salus box to their incoming cables

  • Hello did you manage to get this sorted? As I'm having the same problem, seriously considering returning the device. So much hassle
  • I've tested the wiring, all looks good. I think it's my moritised valve that faulty. I've had a few problems with it before so think it's just at the end of it's life and would probably have stopped working anyway. I'm picking a new one up tomorrow so will let you know how I get on.

    It's been an interested learning curve. Just glad the weathers been so mild otherwise my wife would have killed me!

  • @paulanddace you're probably right about the motor on the 3-port valve. The manner in which they fail can be confusing to diagnose. Individual 2-port valves for each zone are a lot simpler to deal with. Please update this thread if it works - always interested to know how problems are fixed.

  • @GrilledCheese2 @Tahreem As suspected it was my motorised valve actuator that was causing the problem and not the tado system. I suspect this is why the system worked a little eratically for the first day or two (failing actaator motor) and then completely stopped working. Grilledcheese2, thanks so much for all your help. While a chore to fix my self I have, with your help, and some support of my dad (retired electrician) learned a lot about how heating and electrical systems work :)

  • Glad to hear you got it sorted - just in time as the weather is starting to get colder.