Megaflow CL210HE thermostat

[bolst3r]

hope someone can help...

I noticed there was no cold water when running the hot tap this morning so I have done the following:

1) Had a spare valve, wasn't sure if it was ok so swapped it for the CH one to make sure it was ok - central heating working fine with replacement value

2) Put the valve from the heating on the Megaflow - heating works but value on megaflow does nada

3) Switched the immersion heater on and hot water again

This leads me to think perhaps the thermostat needs replacing however doesn't the immersion use the (potentially) faulty thermostat and if it was gone would it stop the immersion from working?

Opening up the lower third plastic cover/flap, I can see what looks like this part and this is listed as a replacement for my unit:

http://www.unventedcomponentseurope.com/hs-95612026.html

This seems like the quickest and simplest thing to change - am I way off in thinking this could be the cause?

I've manually opened the valve with the sprung trigger thinking this should tell the boiler to fire bypassing the thermostats but perhaps this isn't the sequence?

Any help would be apprecaited

 

[simond]

If you want to test the Megaflo stat, join the wires together and see if the motorised valve opens. Don't leave it like that because it is an important safety measure. NB: There are two stats in series for the zone valve inside the Megaflo box, one adjustable, one secretly resettable with a small pin under the cover.

The immersion heater has separate stats and should be ignored.

 

[bolst3r]

joining the wires seems like a good idea to test the stat... Am I right in thinking that even with the valve manually open this wouldn't trigger the microswitch then boiler to fire? You say there are multiple stats, I can see the main one with the blue temp dial as illustrated in the link above but isn't this the immersion stat? Can't for the life of me find the cylinder stat as I was convinced there would be one for the immersion and one for the cylinder...

 

[bolst3r]

ah, I get it now the big one is the immersion, and the two above (one of left with red set) are the other two, is one more likely than the other to cause an issue?

 

[bolst3r]

below is a pic i've nabbed from a vid online but mine is pretty much the same, just a different colour immersion stat (no. 3) Is there an easy technique for replacing this, I assume no.1 is the thermal cut-off, so i'm best looking at No.2 first?

Thanks for any help