Bypass radiators waste money?

flo22

I have a smart thermostat (wiser) as well as smart trv's on all radiators other than 2 bathroom ones.  The smart thermostat is only useful for controlling multiple radiators in a group e.g. 2 in living room or an open plan configuration, that's what Wiser told me when I was setting them up.  To be honest it is not that useful to me and I just removed it from the app

RainTown

Hi

In meantime I confirmed my Baxi 430 boiler does have integrated bypass

“

5.2.4

The boiler utilises the primary side of the DHW plate heat exchanger as an automatic integral bypass. 

“

But Baxi support were helpful and said it is not designed to replace the bypass radiator, rather just a safety feature, and they would not recommend running system without a larger bypass (eg a radiator!!)

thanks ThisIsWeird for idea/comment. 

yes, living room currently has a smart TRV. It’s also biggest (and coldest, large Windows) room in the house. 

You are not “missing anything” .

However my usage pattern is uncommon. I am for now very rarely in the living room. and im loath to even indirectly heat large spaces that are not or rarely occupied. It’s mostly used like a sort of holiday home, prepare/eat some food, sleep, shower, ….

Last night I did experiment by heating just the bedroom. The hall (bypass) rad get hotter , the hall space (which is larger than the bedroom) heats quicker. That energy usage is of low practical use. My guess is more than half my cost for heating the bedroom was actually paying for implicitly heating the hall. 

That’s why I’m now almost set on swapping smart TRV / bypass between bathroom / hall. 

ThisIsWeird

RainTown said:

Hi
In meantime I confirmed my Baxi 430 boiler does have integrated bypass
“5.2.4

The boiler utilises the primary side of the DHW plate heat exchanger as an automatic integral bypass. 

“But Baxi support were helpful and said it is not designed to replace the bypass radiator, rather just a safety feature, and they would not recommend running system without a larger bypass (eg a radiator!!)

thanks ThisIsWeird for idea/comment.
yes, living room currently has a smart TRV. It’s also biggest (and coldest, large Windows) room in the house.

You are not “missing anything” .
However my usage pattern is uncommon. I am for now very rarely in the living room. and im loath to even indirectly heat large spaces that are not or rarely occupied. It’s mostly used like a sort of holiday home, prepare/eat some food, sleep, shower, ….
Last night I did experiment by heating just the bedroom. The hall (bypass) rad get hotter , the hall space (which is larger than the bedroom) heats quicker. That energy usage is of low practical use. My guess is more than half my cost for heating the bedroom was actually paying for implicitly heating the hall.

That’s why I’m now almost set on swapping smart TRV / bypass between bathroom / hall. 

Ah, ok.

Yes, I wouldn't want to rely on the built-in by-pass - it's essentially a safety device, should it be required. And it usually isn't; whichever room has the Wall Thermostat will also have no TRV, and the rads in there will be tweaked to provide the best output to suit that room whilst also providing enough boiler time for the rest of the house. But, that rad will always be 'open' to some degree = that's your by-pass.

So, when you are living there, which rooms do you use - where do you spend the day or evening? The kitchen? If so, is it separate from the rest of the living area? Which rads/rooms do you heat up?

Whichever room it is, then put the Hive in there, and remove/disengage the TRV so that rad is always open. Remember, it doesn't need to be fully open - the lockshield can always be tweaked down to make it less powerful.

If you don't want to heat the hallway, then either fit a Smart head on it, or tweak the manual control down to luke-warm - it'll still act as a by-pass if needed. 

But, for most such setups, the living area - where the Hive will be located - will also be the by-pass, as the rad is always open to some degree. In your case, you need to decide which room you heat when you are at home, and that's the Hive/ByPass rad. 

Failing that, in general the smallest room/rad - which would also be considered the most useful - is the one to generally make a by-pass, and that's the loo. We want nice warm dry towels at all times...