"Anode" wrote in message
news
Is there some setup of a wet central heating system that will let
radiators be warm most of the time, and not cycling between over-hot and
over-cold, as mine are now?

At present I have a 15years old gas fired non-modulating boiler with a
pumped, vented, system, controlled by a wall thermostat. The controls on
this system will not avoid radiators that are either on and far too hot,
or off.

Thus the radiators cycle between being much hotter than is needed for just
compensating for heat losses from the rooms, producing unpleasantly hot
air around the radiators, and then cycling to a period of being colder
than they need to be.

Is there any setup that would give me the necessary heat output but in a
more balanced way, so the radiators will be on for longer but at an
appropriately lower temperature, with the period in the cycle when the
radiators are off being correspondingly much reduced?

As the age of the boiler is such that it could well be replaced, what kind
of setup should I be considering?

Get a heat bank (thermal store). Heated by a Glow Worm condensing boiler
(excellent and cheap enough. Rebadged Vaillants). The heat bank to have two
cylinder stats to eliminate boiler cycling. The boiler comes in on one long
efficient burn. The boiler only heats the cylidner in one continuous burn,
not the rads directly.

The CH circuit taken off the store with thermo rad valves on each rad, using
an auto variable speed Grundfoss Alpha pump. The CH circuit takes what heat
it needs from the store, so always a continuous on-tap store of hot water
with no heat fluctuations.

The heat bank heats incoming cold mains water instantly, so no need for
storage tanks. In the morning the rads are instantly hot as the heat in the
store of water is up to temp and pumped immediately around the rads. The
thermo rad valve take care of local room temperature control.

This gives you:

1. Instant high pressure DHW at the taps and shower.
2. Temperature control at each room.
3. Boiler operating at ideal conditions with the ideal flow through the
boiler.
4. Boiler lasts longer as controls do not constantly switch off and on.
5. Boiler is simpler and easy to fix when down.
6. Full electric backup of DHW "and" CH if electric immersion fitted in the
Heat Bank.
7. No cold water tanks.
8. No room stat.
9. No complex expensive electronic controls.
10. Instant CH when switched on in the morning having a store of on tap hot
water.
11. Local room temperature control.