Major Megaflow problem - what to do next?

[condor]

I've been an unhappy Megaflow owner for some time, and it hasn't been a good investment as replacement for my old copper immersion heater about 10 years ago. It has gone through a few immersion heater rods- the last one I replaced recently which has gone through 2 heating up cycles and is now broken and I'm back to cold water again. These rods aren't cheap, £65 was the previous one from an electrical shop. When it failed it burnt out the female spade terminal on the Megaflow tank electric panel which I replaced. This was a temporary fix and I hadn't crimped the short plastic sleeving to make it permanent.
Following the latest failure, this sleeving has been heat shrunk onto the tank panel and looks a bit burnt. The live wire looks a bit sorry for itself too. Once again the main fuse didn't blow in the consumer unit.
It's certainly in need of a professional electrician to fix it.

My main question is, what could be causing this failure? Can it be fixed or is it time for me to rethink a new hot water system?

[silversurfer1]

The megaflow is just a bucket of water with an internal expansion vessel, if you change it out your just be changing the bucket to one with new immersions, i would be getting an electrician in to check the wiring supplies.
ss

[Smiler.]

How many immersion heaters are fitted, one or two?

Do they have integral thermostats to switch off when the desired water temp is achieved or is there an external control?

Assume the heater(s) are 3kW.

[condor]

It's the simplest model - so just the one immersion heater. There's a 24 hour timer so that it comes on with Economy 7...which also has a dial that allows up to an hours boost. Thermostat is an 11" rod type.
When I put the new rod in - I tested it with the boost to check it worked, which it did. Left it to heat overnight and it's possible that the timer was affected from the last failure.

I'm not sure whether it's a plumbing and heating engineer who do Megaflow servicing I need or an electrician. Or will the plumbing and heating engineer be both?

[Gingerbread Man]

Megaflo.

Sounds like an electrical problem. Have you fitted Megaflo branded elements? Does the water heat to the correct temp, not over heating? The tanks free of scale?

They shouldn't go that regularly, not even in a normal cylinder.

I'd get a sparks in.

[Smiler.]

^ ^ ^
wot he said

I had a quick look online & it seems that there is an integral thermal cut-out on the legit ones.

The control circuit should have temperature sensing to interrupt the power to the heater irrespective of the timer or override on setting. Not sure if that would be via the integral thermal cut-out (would hope not) or if the thermal cut-out is auto reset.

To which temp setting is the element set?

[condor]

Gingerbread Man said:

Megaflo.

Sounds like an electrical problem. Have you fitted Megaflo branded elements? Does the water heat to the correct temp, not over heating? The tanks free of scale?

They shouldn't go that regularly, not even in a normal cylinder.

I'd get a sparks in.

I bought a Heatrae Stadia MegaFlo advertised thermostat 11" rod from Amazon which had very good reviews- will go back and check it again.
The water now doesn't heat up at all - so not overheatinh.
Have a water softener in place with the MegaFlo pipework, but likely to be scale in the tank as I'm in a hard water area.

[condor]

Smiler. said:

^ ^ ^
wot he said

I had a quick look online & it seems that there is an integral thermal cut-out on the legit ones.

The control circuit should have temperature sensing to interrupt the power to the heater irrespective of the timer or override on setting. Not sure if that would be via the integral thermal cut-out (would hope not) or if the thermal cut-out is auto reset.

To which temp setting is the element set?

Not sure I can check visually about what you've written re thermal cut outs.
Temp setting on the thermostat is what was already put there when I received it. I think the little arrow points towards the left- will check tomorrow. I'll hazard a guess at 50 deg C as that is what the previous ones were.

[Smiler.]

condor said:

Not sure I can check visually about what you've written re thermal cut outs.
Temp setting on the thermostat is what was already put there when I received it. I think the little arrow points towards the left- will check tomorrow. I'll hazard a guess at 50 deg C as that is what the previous ones were.

Thermal cut-out in pic below




Does your arrangement look something like this:



This would suggest that there is a sensor & thermal cut-out for a gas-fired boiler heat source but the equivalent for the electric element is integral to the immersion heater.

At 50°C, there is no way cable insulation should be melting.

Assume that yours is electric only with no gas boiler? Can you post a pic of your wiring terminal arrangement?

[Pheo]

Given this is an un vented hot water, shouldn't you be getting a competent person to look at it? Requires a G3 ticket...

[condor]

Sorry for not updating - but am house sitting this weekend and laptop wouldn't connect since Friday morning, fortunately it does now
Thanks Smiler, it is a very simple set up with the blue top coloured thermostat and the brown and blue wires going into each separate screw hole. I'll try and take a photo next week when I'm at home, but I'm only home for a short time before I'm off house sitting till the New Year.

[condor]

Further update - eventually got a professional plumber/sparky ( with the necessary certs)round and have agreed for him to order a new immersion heater base plate for the cylinder. £230 and should be sorted in a couple of days time.
Not too bad I suppose, but I still wish I'd never agreed to a Megaflo in the first place. It's been nothing but trouble since it was first installed.

[Younez]

Sorry for thread resurrection. An element on my megaflow has gone and I have struggled to find someone to fit a new one. I've had a couple of plumbers come who have made excuses and did not seem confident, can't find part or buy a new boiler etc

Any recommendations on a specialist who knows about these and covers west london.

Thanks.

[Gingerbread Man]

If it is actually a megaflo. Ring them and they'll have service technicians or a local plumber with the contract.

[Andeh1]

This is why I always have boiler & heating cover for the £10-15 a month, they have a first 2 week no use limitation... But after that your problem would become their problem....!

[condor]

As this thread has been resurrected I'll give a further update on my Megaflo. It hasn't gone wrong since Jan 2017, although water drips out of the overflow pipe onto the drive. If temperature below freezing I won't use it as the overflow pipe ices up. I don't leave the Economy 7 timer to do it's thing, but switch it on for an hour each day. That is probably me being over cautious now.

[blueg33]

condor said:

As this thread has been resurrected I'll give a further update on my Megaflo. It hasn't gone wrong since Jan 2017, although water drips out of the overflow pipe onto the drive. If temperature below freezing I won't use it as the overflow pipe ices up. I don't leave the Economy 7 timer to do it's thing, but switch it on for an hour each day. That is probably me being over cautious now.

If water drips out, you need to reset the air bubble. Mine needs doing twice a year. Simple exercise, close the water supply, open the furthest hot tap, and the hold the vale (spring loaded round knob) open until water stops running out of the tap. Close the tap, turn water supply back on.

[Younez]

We did have a service contract with BAXI but they said the element is no longer produced by the manufacture so are unable to help. Loads of alternative but they cannot touch.