Megaflo

[mravant]

Hi All,,,,

I purchased a flat around 6 months ago, which had an old white lid Megaflow tank (electric only), 2 immersions (top up at top and economy 7 at bottom).

When I got the flat both stats were shot and they were replaced and all was good (OEM ones, purchased from Unvented Components) .

Now again it appears that they may have failed as the tenant has said that from a month in the bottom one stopped working and they have been using the top one and now that has also stopped working.

Question is can it be the heating element which has failed, as visually they look original and the bottom one does not look great.
Is there a way of eliminating the stats??

Thanks

 

[Agile]

They need electrically testing.

But they also have an integral overheat stat and that may have tripped.

If that were the case then the temperature may need turning down slightly.

Tony

 

[mravant]

Hi Tony and thanks for your reply.

The safety has not been tripped on the stats and when they were installed they were set lower to around 3.5.

 

[Agile]

How do you know they have not tripped?

Tony

 

[mravant]

The safety pins have not popped out on the stat!

 

[Agile]

From memory on a genuine Megaflow they do not "pop out".

Tony

 

[mravant]

Thats why I can't see one popped out!!!!!!!!

It's a Cotherm.

 

[Agile]

Did you actually push them back in to see if they were tripped?

Tony

 

[mravant]

Yes I did push in a small screwdriver to see but did not feel any movement so presumed it was not tripped.

 

[Agile]

In that case I expect that they were not tripped.

From memory their normal position is about 1 mm lower than the surrounding and flush when tripped!

Has anyone confirmed there is really a supply getting to them?

Tony

 

[mravant]

Yes supply reaching the stat.

I have just tested the stat and am not getting any Ohm reading so i think the stat has gone in a short period of time rather than the element.
Am i correct in assuming that no Ohm reading equates to dud stat?

 

[oldbuffer]

The thermostat should have virtually zero resistance when the contact are closed, and an infinite resistance when they are open.

The resistance of a standard 3Kw immersion heater element is around 18 ohms when cold. I'd take anything between 16 and 20 as OK.

 

[mravant]

So nothing showing up on the meter proves its a dud???
Going to compare it with a known working stat on Sunday to see the reading difference.

 

[Agile]

I have to say that my experience with that model is that for every failed element there are about four or five failed stats!

Easy enough to remove stat to test resistance of the element.

Tony

 

[mravant]

Tony how do you test the resistance of the element and what should it read?