not shutting down

[118roy]

Hi, I have a Honeywell ST 699 programmer, when they system is shut down for the summer ( sliding all control to off ) I find the honeywell 3 port valve head stays energized and gets quite hot at times.
Is there a system shut down sequence ?
I am thinking of changing the programmer to a more modern honeywell ST 9400.
Do these slot in to the 699 back plate ? or would I require a engineer if so what is the going rate to change a programmer
Thank for any advice.

 

[Nozzle]

Changing a programmer is within reach of the DIYer (if you're confident you can read the circuit diagram)

Nozzle

 

[118roy]

Changing a programmer is within reach of the DIYer (if you're confident you can read the circuit diagram)

Nozzle

Many thanks , but it looks technical to me , and if I mess it up it would be an expensive problem

 

[robin7]

Replacing a Honeywell ST699 with a ST9400 isn't difficult - although the new programmer will NOT fit onto the ST699 backplate.

There are 2 versions of the ST9400 available - the ST9400C is the 7-day version.

Full instructions on the replacement can be found here: http://docs-europe.origin.electrocomponents.com/webdocs/0b6c/0900766b80b6c925.pdf

 

[D_Hailsham]

Hi, I have a Honeywell ST 699 programmer, when they system is shut down for the summer ( sliding all control to off ) I find the honeywell 3 port valve head stays energized and gets quite hot at times.

When you say "slide all controls to off", do you mean Heating and Hot Water? If so, how do you heat the water in the summer - electric immersion?

That may not be the cheapest way. Use the boiler to heat the water - just turn Heating off at the timer.

As for your problem, there's nothing wrong with your timer or the valve. It's a quirk of the midposition valve that it stays in the CH position when it has been running in CH only. The solution is to turn HW ON, which resets the valve to HW. You can then turn HW off if you don't want to use the boiler to heat the water.

 

[Boilerman2]

When you turn off the sliders on the programmer, you apply a 230v signal to the Motorised valve actuator to drive the hot water port closed the heat is simply the 4w motor holding the valve in the required position
turning off the fused spur will stop this, but after a couple of months the accumulator or battery in the programmer will be deeply discharged and could result in the failure of the programmer when it is put back on for the winter! - as others have said it is probably cheaper to use your Gas or Oil fired boiler to heat the hot water anyway!

 

[118roy]

I shut the boiler right down in the summer using the elec shower and the kettle to boil water.
It's all fun being an OAP.
Reset the CH and HW as you advised and felt the port valve head and it's not hot any more so it is now shut down completely.
Many thanks for your help and sharing your knowledge

 

[D_Hailsham]

When you turn off the sliders on the programmer, you apply a 230v signal to the Motorised valve actuator to drive the hot water port closed the heat is simply the 4w motor holding the valve in the required position

It's 230V on the grey wire (from HW OFF or HW stat SAT) which holds the valve in CH position. Turning power off, or turning HW on, is enough to return the valve to rest in the HW position.

See Boiler FAQ 17.