Smart Valve in Same Room as Smart Thermostat

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Just about to extend my Tado system to the whole house. I have a Worcester Bosch condensing boiler with a wired thermostat. There is no by-pass circuit fitted in the plumbing. My Thermostat is Tado Smart and I have 4 Tado Smart Rad valves. Want to extend by adding 4 extra Smart Valves.

Conventional wisdom is not to put a TVR in the same room as the thermostat...and boiler installation notes day you shouldn't. I currently have TVRs on all rads except the Hall, the coldest room where the thermostat is located.

My logic would say that if there is a demand on the boiler for heat from a radiator rad valve then there must be a radiator set in the open position somewhere...so no problem, no overloading the system by overheating...so the Hall can have a Smart Rad Valve (especially if I pair that rad valve with the Smart Thermostat, making the Smart Thermostat the Master)

But what if the Smart Rad Valve that is calling for heat has a stuck needle in the TVR, and nothing else is? Nowhere for the heat to go... is the Tado system clever enough to spot that?

Now I am by no means a plumber,,,so any advice welcome as I can't find an answer.

Answers

  • wateroakley
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    @gladysethel every heating system has to enable dispersion of excess boiler heat by some method, typically via a bypass. Many boilers have a internal bypass, some require are external bypass Without stating the exact boiler model, impossible to know the requirement.

    Your heating engineer should design the system and define if a bypass is needed. A stuck trv needle is a fault condition and Tado is not able to spot that. Our boiler has an internal bypass. We also keep one rad open and unrestricted.

  • gladysethel
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    Thanks for getting back to me. Leaving one rad open was the conclusion that I was coming to myself. Would that best be one furthest or nearest to the boiler, the hottest or the coldest room, or doesn't it matter. By the way the boiler is a Worcester Bosch Greenstar 30CDi and definitely no external bypass.

  • wateroakley
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    The answer appears to be ‘‘Leave one rad open’ - probably the rad in the room with the room stat, or a bathroom; Or fit an automatic bypass’, maybe. If in any doubt, consult a heating professional who knows your system.

    From the manual: On new installations, or extensions to existing systems where a radiator previously did not exist, each radiator should be fitted with a TRV, except the one fitted in the same room/area as the thermostat. On boiler only replacement jobs, it is recommended, (but not mandatory,) to fit a TRV on each radiator.

    An automatic bypass may be required, (downstream of the pump), in order to maintain the minimum flow-rate through the appliance.