Upgrade control system

[niallmoran]

Afternoon folks

At present we have a rather aged Baxi system boiler that runs 5 radiators via 8mm microbore and heats the indirect HW tank in the loft. The only controls are a room thermostat in the hallway and a Horstmann Centaurplus C27 which our engineer fitted about 6 months ago to replace a broken anologue time switch.

There are no control valves in the system and the hot water connections are T-ed at the boiler with one set of pipes going up to the loft tank and the other going down to the CH pump and the microbore manifolds.

The problem we have is that the water and CH are not independant and although the room stat will switch off the CH pump and allow the water to be heated on it's own, when the CH is on the HW gets very very hot!

My question is, what is the best way to re-jig the system to allow better control? Could i just pop a valve in the hot water tank feed so that the stat stops the flow to the HW tank? Or would i need to install a 3 way valve at the outlet from the boiler? Also, would a pressure relief valve/by-pass be required?

Any info/advice greatfully received!

Cheers
Niall

 

[gas4you]

I personally would re-pipe the control circuits to a fully pumped system, using a 3 port mid position valve (Y plan) or 2 x 2 port valves (S plan) and fit a 7 day programmer such as a Danfoss or Honeywell.

 

[niallmoran]

Cheers for the reply Dave - i think i would be out of my depth with that level of upgrade but i'll maybe have a word with our heating engineer and see what that level of upgrade would cost. Or maybe we should just get used to having exceptionally hot water!