On Mon, 31 Dec 2018 20:30:16 +0000, Roger Mills wrote:
On 31/12/2018 16:17, David wrote:
On Mon, 31 Dec 2018 15:55:26 +0000, David wrote:
snip
Addendum: http://wiki.diyfaq.org.uk/index.php/File:Wiring_Links.jpg
Links on the back of the wiring block.
Looks to be a link between 3 and 9 which is puzzling me.
Cheers
Dave R
Can you remind us whether this has *ever* worked properly. If it hasn't,
it's most likely that it's wired incorrectly. If it *has*, it has
presumably developed a fault - most likely associated with the 3-port
valve.
snip
I can't honestly say if it has ever worked as designed - it is not my
house.
I have a suspicion that it may have been faulty for a long time because
when the hot water is on via the programmer, the CH is on via the
programmer, and there is a call for heat from the HW thermostat then the
valve is (usually) in the mid position and the radiators heat up.
It is only because the house started from very cold and took an unusually
long time to heat up that I started to investigate, first by feeling all
the radiators (which need balancing but not a major problem) and noting
that they weren't heating up consistently when the programmer and
thermostat were calling for heating.
I suspect that the owner thought that the heating wasn't very good but
couldn't be arsed to get someone to investigate in detail.
If you are in constant occupation and use a significant amount of hot
water every day then the house stays warm.
Anyway, I'm going to replace the 3 port valve head (wish me luck) and see
if that does the trick.
I am not enthused to undertake a full diagnosis of the wiring - I would if
it was my own system but this is a house which is a long way away from my
home and needs to be left empty but frost free over the winter.
I would just leave it with the heating and hot water programmed, but every
now and then the 3 way valve moves to the HW only position and doesn't
seem to move back. I am assuming that either the valve head is confused/
faulty or it is seeing a call for HW but no call for CH. Which is again a
puzzle because
AFAIK this can happen when the CH is calling for heat.
Oh, and thank you for your comprehensive explanation; just one thing,
though; I thought when there was no call for HW or CH the valve, unpowered,
returned to the mid position. To go HW only or CH only required power to
move the valve to close off the other feed. But I may well be wrong.
Cheers
Dave R
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