Central Heating Upgrades - Circulating Pump Location

[harrybike]

Recently moved into a house with a combined pumped central heating and hot water circuit. The 20 yrs old Potterton nice and reliable but inefficient floor standing boiler ultimately requires replacement but I want to leave this for the minute until other work is completed (kitchen extension, what fun).

The only control at present is TRVs, boiler timeswitch and boiler thermostat. Also 15mm connections to the vented hot water cylinder and a 15mm vent/feed pipe that only splits at the expansion tank in the loft.

Now it is coming to summer this is becoming a pain with various sticking TRVs. I'm looking to rejig the piping to add 2 port control valves on the central heating and hot water. Running a new supply pipe up to the airing cupboard where I'll locate the control valves, make existing supply pipe the supply to the rads only and revise the vent/feed pipe arrangements (should be 22mm vent plus 15mm feed shouldn't it?)

I'd prefer not to mess around with the existing circulating pump located on the return side of the boiler downstairs in the kitchen. Recently the practice seems to be to locate circulating pumps on the supply side of the boiler, either immediately adjacent or in the airing cupboard by cylinder/control valves.

I'm curious as to anyone's thoughts on whether it is OK to maintain the current pump locations or whether it should be moved. I can move it if I really have to but as this is a short term measure before a new boiler I'm like to minimise effort......

Any advice would be appreciated.

Thanks

 

[werewolf]

Altetrations wouldn`t prevent trv`s sticking.This wil be due to sludge in 20 year old system which will need flushing to remove.Personally i would leave system as is for now and when time / money permits rip out old boiler and drag system into 21st century.

 

[harrybike]

Thanks. Absolutely agree- the system both needs a flush and the older TRVs replaced with another TRV or just a rad valve depending on where located. I'll do that at the same time along with moving a few rads.

It does not seem great to me controlling the hot water cylinder temperature purely from the boiler thermostat. And a room thermostat and hot water cylinder stat will be added along with the control valves and a proper programmer.

I'll do the work myself so cost is less of an issue but of course I want to do the minimum!. What I don't want to do is either make the situation worse or work that will be abortive when we get to replacing the boiler in 18/24 months time.

And going back to the pump location issue -is this likely to cause problems?

Any advice would be much appreciated.

 

[werewolf]

If you are concerned primarily with dhw temp then fit a 15mm cyltrol valve on dhw flow into cylinder. ( it`s like a trv for cylinders.)

 

[harrybike]

Thanks Werewolf.

Thought there may be such a device. Just searching it looks as though the cost of a cyltrol valve won't be that much less than a 2 port control pack though, which will also get around our mechanical timeclock programmer.

Sounds like there is no big issue pumpwise......

 

[Soggy_weetabix]

A Tap Stat might be cheaper

Dave

 

[EliteHeat]

There is one on eBay at the moment

eBay Item

Quite cheap, no wiring or pipe mods