Does OpenTherm work with a hot water cylinder
I currently have a UK Tado wireless receiver set up to control both my heating and my hot water (we have a conventional boiler rather than system or combi). Prompted by this twitter thread (https://twitter.com/tado/status/1584453780413612035) from Tado I decided to purchase the OpenTherm compatible receiver to gain the benefits from modulation. Having recieved my unit I am now not clear whether or not it supports heating a hot water cylinder, the associated manual doesn't seem to mention it? Am I out of luck, is OpenTherm + a hot water cylinder not possible with Tado?
Answers
-
Not possible with a system boiler (with very few exceptions - some vaillants can with an extra module fitted). The only way to do it would be to replumb your system for priority domestic hot water, assuming your boiler supports it.0
-
It's a heat only boiler though, not a system one?0
-
With both system and heat only boilers you need a constant supply of hot water to the cylinder in order to have hot water without the need for the cylinder to heat it (assuming it can). With a Tado modulating system it can only tell the boiler to modulate its heat output, it can’t tell the boiler to switch to supplying hot water to the cylinder when it’s required.
There is a way around this with priority domestic hot water but I think it usually requires a new cylinder and replumbing.1 -
The issue is not if the boiler supports digital that Tado can support, the issue is that you need to not only control the boiler via digital but also the zone valves via a relay of sorts. This is usually done in a fancy wiring centre such as vaillants vr66/65. The Tado unit is either relay or digital. Until Tado make a unit that can digitally communicate with the boiler and also be opening valves outside in the system s plan etc will be an unfulfilled market. I have a s plan in a 2019 new build, Tado ebus is a no go for me, on relay. Also maybe digital benefits are not worth the effort for some.
1
