Heatin Problem

[commoner]

Hi...my hot water and central heating is controlled with a Drayton mid position activator which moves a valve depending on whether I want hot water or central heating only or both or none......for a few weeks now I find that whichever I choose I get both hot water and central heating....the indicator on the side of the unit moves to the correct position but still I get both on...seems like the actual valve is stuck in the mid position.....

Any advice please..I could get a plumber but could be pricey and I don't have lot of spare cash as a pensioner....

Thanks in advance....

[boxtops]

Commoner, I can't help, but some plumbers offer discounts to pensioners - mine offers 10% - it all helps.

[commoner]

Thanks boxie....10% would be good if I do have to bite the bullet. ;-(

After Christmas though now!

[buildersmate]

These things are made in two parts - the T-shaped 'plumbing' valve and the electrical actuator. Depending of your willingness to attempt DIY you may feel able to undertake some simple tests/checks to diagnose what's wrong.

Drayton is made by Invensys - a respected industrial controls manufacturer in the UK and these things are generally quite reliable. You can get a datasheet for your unit here: - http://www.draytoncontrols.co.uk/product.aspx?id=1561 (select the one three-port one you want and it will download as a PDF file).
You can separate the two parts, the actuator head from the valve - there will either be a clip, a release device or maybe two screws. There is no danger in doing this in that no will be no worse off than you are now and no water can escape. Having done this you will see a spindle on the valve with a flat (or maybe 2) on it. With an adjustable spanner, you can try turning the spindle around a full 360 degrees (complete turn). Thay will tell you whether it is jammed with limescale - this may free it enough.
With the actuator head off, you can try switching the controls of your CH to see what happens to the actuator motor shaft that engages into the flat on the spindle - you should see it turning very slowly (takes about 20 seconds to move from one position around a quarter-turn) and you can hear a slight whirring noise from the motor. That will tell you whether the actuator unit is broken or maybe just incapable of turning due to exceesive resistance from a jammed valve spindle.

This would be the first test that a heating technician would do. You can be no worse off at the end of this test as you can replace the actuator back onto a spindle and bring-in the cavalry. However freeing the spindle with a spanner may solve the issue, or you may find that the fault lies in the head.

Provided the current model is the same form/fit as your unit, changing the head unit only is necessary - an electrical job involving 5 wires - not a heating technician job. You may have to buy a complete unit (at a cost of about £60) and just use a new head component.

[commoner]

Wow bm...that is what i call a helpful answer...I'll follow your instructions and see how it goes....then as you say get some professional help if I need to....maybe at a pensioners discount as boxie said ;-)

Thanks again....much obliged.