What central heating system do I have ?

[Spindles]

That's brilliant. Thanks so much to all of you for taking the time and giving such detailed advice. It's reassuring to know my Hive is now set to the correct setting for a pumped system and my HW will no longer have to come on with the CH.
I'll get someone in to investigate the boiler turning off and on before it gets to the thermostats temp when I can.
Thanks again everybody.

 

[Mister Banks]

That's brilliant. Thanks so much to all of you for taking the time and giving such detailed advice. It's reassuring to know my Hive is now set to the correct setting for a pumped system and my HW will no longer have to come on with the CH.
I'll get someone in to investigate the boiler turning off and on before it gets to the thermostats temp when I can.
Thanks again everybody.

The Hive is a TPI thermostat so the boiler behaviour could be normal. Look up TPI online for an explanation on how it works.

 

[Spindles]

Ok, I'll do that. Thanks again.

 

[Harry Bloomfield]

That is wrong, you do not have a gravity system.

If the HW is too hot, either the thermostat is busted (the grey Satchwell box with the black dial on it), or it's been wired incorrectly somewhere.

The thermostat is mounted far too low on the cylinder, is will not be sensing the true temperature of hot water. It should be around 1/3 the way up from the bottom of the cylinder.

It should be an easy fix - the stat will be clamp around the cylinder by a spring similar to the old net curtain springs. Just slide spring and stat up the the correct place on the cylinder. Shorten the spring if it is loose.

 

[Spindles]

Thanks Harry. I'll add that to the list that needs attention. It's getting longer each day!

 

[stem]

I have an issue where the boiler is turning off before my CH is getting up to the required set thermostat temperature and just turns off and on randomly taking an age to finally get to the right room temp.

That doesn't need attention, that's how it is supposed to work to save energy. It does it to prevent the heating overshooting the set temperature, which happens especially in well insulated properties in warmer weather. @Mister Banks has already provided you with the info. This feature can sometimes be irritating in older properties that aren't very well insulated or are slow to warm up. But it should get close to the set temperature before it starts doing it.

So in summary, all you need to do is slide the cylinder thermostat 8 inches up the cylinder and set the Hive to 'Fully Pumped'.

 

[Spindles]

Thanks very much everyone. The Hive is now set to 'fully pumped' and I'll have a look at the cylinder thermostat over the weekend and try and move it up a bit.
I'm very grateful to you all for your advice.