Keston separate temp for heating & hot water

JoeMic

JoeMic

Joined
8 Feb 2021
Messages
7
Reaction score
0
Country
United Kingdom
In an effort to control my extremely high gas consumption, I turned down the "flow setpoint" temperature on my Keston Heat 55 boiler from 70 degrees to 48 degrees. This has substantially reduced my gas usage.

I have underfloor heating and this new temperature seems to be high enough for that, at least for now. The boiler also heats water intended for hot water consumption (which is stored in a Megaflo Eco Plus cylinder), and the new 48 degree temperature means that this water is not as hot as I'd like it to be. The cylinder temperature is set to 60 degrees.

Is there a way to set a Keston Heat 55 boiler to heat the water intended for hot water consumption to a higher temperature than the hot water which goes to the underfloor heating? This would save me keeping the boiler's "flow setpoint" at 70 degrees the whole time, which is hotter than my underfloor heating seems to require, but still allow me to have hot water at a suitable temperature.

Sorry for the basic question - I've tried looking up the Keston boiler manual but couldn't work it out from there.
 
Yes, you'll need the tank sensor kit. That will allow the boiler to sense the temperature of the cylinder. It does mean running a new wire from the boiler to the cylinder to install it, unless the existing cylinder thermostat wire runs to the boiler cupboard in which case that can be repurposed. A Heat 55 is big enough to heat a very large property...around 500-800 square metres of underfloor heating. Does that sound right for your property? If not then your high consumption may be due to an oversized boiler
 
Last edited:
Thanks. Sounds like I need to involve a professional...

I suspected that the boiler was too large. We don't have that much underfloor heating (house area is c. 400sqm in total, underfloor heating will be less than that). For some reason we also have a huge cylinder (500 litres) and I presume that also costs a lot to keep going.
 
It would certainly be worth getting a proper survey of the system done and maybe a price for replacing the boiler (& maybe cylinder) if it's considered to be appropriate. Obviously a proper cost/benefit analysis would be needed before committing to any changes. I'd suggest a heat loss calculation be done using https://www.heat-engineer.com and a good look at your controls setup to see what improvements could be made there. Where are you based/ what's your nearest town?
 
Thanks, that sounds like a good idea. I'm in North London (Barnet).
 
You must log in or register to reply here.
Back
Top