Understanding my heating system and how Tado will help/improve it


Hi guys,

So I am trying to get an understanding of how our heating system works so I will try and explain it as best as I can.

We have a Logik Combi boiler, with underfloor heating downstairs and 5 radiators upstairs and 2 towel rails on same circuit in bathroom and ensuite.

We have 3 wired thermostats, one in living room, one in hallway and one on first floor. We have been in our house for over a year but how the heating works is VERY confusing. The stat in living room when on turns on the UFH, but not in all places such as kitchen and it also turns on the rails and rads upstairs. The stat in hallway appears to control the ufh in kitchen, hallway and downstairs loo, unsure if it turns the rads on. The stat upstairs does turn on the upstairs,but unsure if it turns on the UFH. It is clear the system isnt wired correctly and makes it very difficult for us to control it. We only heat the towel rails upstairs and maybe the spare bedroom rad if someone stays, but we have no control of when these come on, we just have to turn on the UFH as well.

I'd like to be able to turn on the rad and the rails seperately to the ufh so I assume 3 SRVs for these would be the resolution? The rails dont have TRVs currently so need to ask a plumber about changing these. With regards to the downstairs, I could get a wired thermostat in place of the living room, but what would I do with the other 2 stats? Just leave them off and not have ufh on in kitchen etc?

Sorry for the essay, we are just wanting to try and get our heating sorted out


  • @adamfezza88 spend the money on a heating engineer to resolve your zoning issues before considering a smart thermostat. The issue is likely to be trivial, perhaps a mis-wire, but it may take a bit of time to identify. Neither of your downstairs thermostats should affect the upstairs. You should have all the radiators and towel rails on one circuit with a single thermostat. Your downstairs UFH appears to be divided into two zones. Quite normal to have the kitchen and living room on separate zones as families often occupy one of these zones at a time.

  • Hunter
    edited November 2022

    The key here is that the thermostats are glorified switches that connect two wires together. If you replace the current thermo states you will make no change to how the system is wired or plumbed.

    adding SRV will activate the plumbing to whatever that rad is connected to, so if whatever currently comes on with that rad will continue to come on.

    what you can do is stop rads from firing at the same time as say UFH if they are on the same plumbing zone but I am guessing you can;t stop the UFH activating if on the same plumbing zone and the rads demand heat.

    hope that makes sense, best getting an tech look at what is actually connected to what in your system before buying these expensive items..

  • I thought I'd update you on what we decided to do in the end with this.

    We had a plumber look at the system and they confirmed the UFH is not isolated from the rads upstairs by means of a motorised valve so this is why the rads heat if any of the room stats turn on. The only zone control we have is on the UFH zones. (I am going to investigate this in winter to see which zone each room stat does) UFH has 3 valves on the manifold so the room stats control 1 of 3 zones.

    We replaced the living room stat with a wired tado stat and then replaced most trvs with tado srvs for the room control. The other 2 room stats are currently off and maybe replaced at a later date once I work out what zone of UFH they do. Although we have no control of turning UFH off when heating a rad(besides manually turning the valves on the manifold)at least we can run the UFH without the rads which is preferable.