Amptec Model 600 system - sometimes doesnt turn off

[alphacentauri]

Hey please help folks,

I have an Amptec boiler - the only way I can turn it off is by using the big red isolation switch on the wall. This seems to reset it, though not every time.

I have a morning and evening CH & HW timer setting. It always comes on in the morning but as it is set to do so for just one hour, I often pop in before I leave for work and it is still boiling away (even when the timer lights have gone off). I've seen them go off automatically (they make a tick sound and some other noises like a valve reset) but this doesn't result in the boiler turning off.

Sometimes but rarely the boiler will turn off and the entire thing works as I expect it to. This behaviour happens regardless of whether it is an automatic timer setting that triggers it or whether I have manually pushed the 1hr boost buttons (typically late on a cold evening).

Can you folks please help me by making a suggestion to the most likely cause? I've asked a few plumbers on the phone and they seem reluctant to look at the system as they aren't sure about Amptec boilers etc so I need a rough pointer to avoid calling out Electroheat plc as they charge £200 just for the service.

Cheers,

Peter, Liverpool

 

[DeltaT2]

Peter, we'd need a few more details mate. Why not take a couple of digi photos & post them up. Showing your boiler, HW tank, valves, pump etc.

I'd like to establish if you have any controls outwith the boiler, like zone valves. Does your Amptec heat your HW tank?

200 quid to service a Amptec eh??! Nice work if you can get it!!!.........................

 

[simond]

If you have zone valves the most likely scenario is one of them is sticking in the open position, as alluded to earlier.

If you are electrically competent this is easy to check.

Otherwise you need a heating tech with an ounce of knowledge, agreed these can be difficult to find. How people think they can offer repairs on boilers with no electrical abilities is beyond me.

 

[alphacentauri]

Hey guys,

Thanks for the fast reply. I believe the Amptec does heat the hot water (quite fast too).

I had the zone valve replaced a few years ago. Just tried the manual boost buttons and it seems to work without sticking, though going to keep an eye on it tonight.

Uploaded a load of pictures that should help you experts out

//www.diynot.com/network/alphacentauri/albums/12219

Cheers

 

[sandybeach]

Like already stated, the most common cause would be a sticking end switch on one of the motorised valves.

Isolate the power to the external controls. Remove the covers from the zone valves, locate the micro switches, (they'll be behind the motor).

Spray a contact cleaner or WD40 on the switches to stop them sticking.

 

[simond]

Looks like you have a crappy Orkli zone valve and Drayton.

Normally it is the mechanism in the valve head that seizes open, it will normally take replacement rather than a squirt of oil. No harm trying though.

 

[DeltaT2]

You know it always beats me why anyone would fit an indirect cylinder with these 'flow through' type electric boilers?? All that extra money for what?? When you'd just fit a E7 type direct cylinder!!!..........

I guess it's installed by the dafties & paid for by the people with more money than common sense??!!

 

[alphacentauri]

The solution was to replace the Drayton Zone Valve. When the heating stayed on the other day I started lightly pushing knobs and sliders on the devices. The top slider on the Zone Valve was stuck as it pinged out and moved to the right position which immediately turned off the system. It's worked perfectly on AUTO since so I'm getting a plumber to change tomorrow. Thanks for all your help