Buffer tank on central heating return

[funks81]

I am considering fitting a small approx 140l buffer tank on to the return of my central heating in order to prevent short cycling of my Grant oil boiler whilst only 1 or 2 UFH circuits are operating.  I was thinking of using something like this - https://www.tradeplumbing.co.uk/gledhill-144-litre-economy-7-direct-cylinder.html?gclid=Cj0KCQjwguGYBhDRARIsAHgRm49cqWJ9bSAitZW9rcKBsAKQDGxN14qVeWD6VCLC4GFDaULEiV_43VcaAqoXEALw_wcB 

 

I am hoping that this will prevent the short cycling by increasing the volume of water in the system.  I also figured that overnight I could use my Octopus Go cheap rate to run the UFH.

 

In order to maintain boiler return temps I was going to fix a thermostatic mixer valve onto the heating return (the Grant boiler asks for a minimum of 50C return temp).

 

Any comments on the feasibility of this?

 

 

[JohnMo]

No issue with a buffer on the return leg.

 

If your using electric to do heating and not oil, but confused with this bit and relevance to oil and a buffer? 

 

Easier fix to balance the heating system so that all circuits are on and flow at the correct rate for the room heat transfer required.  Then no buffer needed.  Sounds like you have too many thermostats.

[funks81]

Thanks John

 

Great to know about the buffer - does that tank look suitable?

 

The electric would only be used overnight during the cheap Octopus Go period (contactor and smart plug on boiler to turn off during this time)

 

We do have a large number of thermostats in the house - but the way we use the house means we only heat rooms as we need them - its rather costly to heat the whole house all the time.

[JohnMo]

Only things I would say about the cylinder is it insulation is very thin, so make sure any heat loss is usable.  If you intend heating the cylinder to use on the overnight electric the buffer would be better on the supply side of the system.

 

Is your heating system pressurised, if so the cylinder will need to be pressurised also with the same protection.