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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> Central heating creep https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1119561442 Message started by JerryD on Jun 23^rd, 2005, 10:17pm

Title: Central heating creep
Post by JerryD on Jun 23^rd, 2005, 10:17pm

No, this isn't what I call my plumber.......

My heating is off at the programmer and the room stat is at zero but when hot water is on, I get hot rads upstairs. :(

Gas ch system with 22mm mid position valve (Drayton). Fully pumped system.

At the mid position valve the pipe to the ch is hot even though the mp valve is set to W. Does this mean the valve is creeping? I reckon so but would like other opinions.

This valve isn't very old (3 years max) so if I have to replace it, it there a more reliable make/type to use?

Would it be worth 'upgrading' to two zone valves instead of this mid position valve?

All advice appreciated.

Title: Re: Central heating creep
Post by thescruff on Jun 23^rd, 2005, 10:47pm

May just be a bit of muck stuck in the valve, would be worth having a look first, or even cut a lever valve into the heating flow.

S plan would require an auto bye-pass valve as well as system alterations

Title: Re: Central heating creep
Post by billythekid on Jun 23^rd, 2005, 11:11pm

wrote on Jun 23^rd, 2005, 10:17pm:

This valve isn't very old (3 years max) so if I have to replace it, it there a more reliable make/type to use?

Towards the end of my mum's systems life i replaced motorised valve heads about once every 6 months!

wrote on Jun 23^rd, 2005, 10:47pm:

or even cut a lever valve into the heating flow.

:o

btk

Title: Re: Central heating creep
Post by thescruff on Jun 23^rd, 2005, 11:42pm

:o and why shouldnt you cut a valve into the heating pipe BTK :o

Title: Re: Central heating creep
Post by JerryD on Jun 25^th, 2005, 7:44am

wrote on Jun 23^rd, 2005, 11:42pm:

:o and why shouldnt you cut a valve into the heating pipe BTK :o

where would the flow of water go if the lever valve was off but the ch was calling for heat?

Title: Re: Central heating creep
Post by thescruff on Jun 25^th, 2005, 8:04am

Thats what they did in the old days. shut the heating down meant turning the valve off

Lot of system had valves on sections like the east or west wings

Title: Re: Central heating creep
Post by JerryD on Jun 25^th, 2005, 8:10am

I can understand just isolating a 'section' of the heating run but to valve it off immediately after the mid position valve is surely a bit dangerous?

I don't know if it's dangerous, I'm asking, it just seems a bit dodgy?

Title: Re: Central heating creep
Post by Lectrician on Jun 25^th, 2005, 8:28am

When I move dinto my current house, my rads became warm with the water on, mid valve also.

The plumber found that the bathroom rad (which was different to the rest, and plumbed in plastic rather than copper, so installed after the system) was plumber into the A/C.

They used the CH flow, but the HW return. Took me ages to work out why it was wrong - drew a diagram, and all was revealed!

Title: Re: Central heating creep
Post by thescruff on Jun 25^th, 2005, 10:30am

The central heating and the primary return water is the same, the problem comes when you tee into the return after they become common :-/

Obviously any valve would be after the cold feed and vent if installed correctly, and any system should have an auto by-pass valve fitted between the pump and the return.

So where's the danger ::)

Title: Re: Central heating creep
Post by Lectrician on Jun 25^th, 2005, 12:00pm

Thats what happened to mine. There was three 22mm pipes to A/C One is combined flow to mid valve, one is return from cylinder, the other is flow to rads.

The return pipe from the cyl ends up at the boiler, as does all the return from the rads. They both just tee into the drop to the boiler.

As the 3 pipes where at the a/c, but no rad returns, the rad in the bathroom was bodged so the flow was on the CH flow, but the return from the rad was on the cyl return.

Sorry, Im no plumber, so hope that makes sence!!

I was offered the easiest option of having the rad on with the HW, or taking the return from the rad to the other rad return.

Title: Re: Central heating creep
Post by thescruff on Jun 25^th, 2005, 12:23pm

Does to me sparkie ::) ::)