Central Heating

[Glitch]

So using logic (and no heating/plumbing experience whatsoever) I can't see the point of mixer valve for the radiators. Only makes sense for the hot water storage which needs to be cooler than the radiator circuit.
Just use the boiler stat to set the radiator circuit temperature.

Is the pump itself knackered? I assume the wiring is live when called upon?

 

[Jos7000]

It was seized when we moved in 42 years ago!

Is it actually a hot and a cold feed to the valve or has it just been repurposed?

 

[Spectric]

Hot water is always on when Heating is on.

Hi

If this is the case then how does the system prevent overheating of the sealed hotwater cylinder? The safety valve will let go at 100°C otherwise you would have bigger problems.

 

[Glitch]

Hi

If this is the case then how does the system prevent overheating of the sealed hotwater cylinder? The safety valve will let go at 100°C otherwise you would have bigger problems.

Presumably another thermostatic mixer valve.

 

[stevek]

I suspect its the same as was fitted to the Titanic or a left over bit of Doodlebug!,,,Ive done a fair bit of diy plumbing over the years and not seen one, but I would suspect that this was a way of regulating the hot water temp,,,in fact it has that old solid fuel look about it,,Its a pain but you could probably change over to a 3 port valve controled by a cylinder and room stats and programmer which I think would most likely save you a few bob too,,the trouble is if you cannot diy its how much a plumber would charge you,,touching the gadget itself is fraught with potential problems and I wouldn't be brave enough to do it,,

 

[Spectric]

I am always extra cautious with sealed systems, in particular ones that potentially contain stored energy and heating a large volume of water without full control can result in some bad outcomes. This system looks like is was one of the very first, probably before G3!

 

[stevek]

Is it a “sealed hot water cylinder”,,I very much doubt it?

 

[stevek]

Sorry for the multiple posts,,Ive just looked again at your photo and I think its a “Blending Valve” you can see the Red Dot hot feed and Blue Dot cold feed with the Red/blue blended hot and cold from the top and bottom tappings, on an old system the cylinder will be open vented and the cold feed for this valve will probably come from the cold water storage tank to balance the supply pressure, so its not regulating the cylinder temp, rather the temp of the water going to the taps,,,well thats my guess.
Btw you can still get blending valves and I think they might be mandatory in places like old peoples homes,,,

 

[OldWood]

Are blending valves not mandatory now for the taps in all modern builds ?

 

[Jos7000]

Hi Jos,,electric is without doubt the future even without future legislation, we will look back on wet CH systems and wonder why we ever did it, my feeling is that you just pop along to Argos and buy a panel style convector heater, cost very little, no serviceing and if they go wrong you throw them away,,the only thing stopping us is the price of electric,,,I think there have been studies into the relative costs taking maintenence etc into account, and electric still comes out as more expensive,,however with a very well insulated house it might be different? Im assuming your high cost option is for storage heaters and using Off Peak electric?
Steve.

Sorry, only just saw this.
You are correct, storage heaters would be required as my electric is virtually free only while the sun is out.
All my lights are led to compensate for having to pay to turn them on.
I just wish the technology for harvesting rain energy was cheaper and easier to acquire, that said the feed in tariff wouldn't allow me to utilise it without reducing the amount they pay me. I would have to set up an entirely separate circuit. Bureaucratic nonsense!

 

[croft36]

The hot water storage tank i

Is it a “sealed hot water cylinder”,,I very much doubt it?

No it is vented. The hot water to the cylinder coil is not pumped.

 

[woodieallen]

I'd have been divorced by now if I hadn't sorted the problem out in over a year