Megaflow not heating up

[Ken77]

Hi,

I was wondering if anyone could shed some light on this problem I have encountered. I inspected a property which had no hot water. The system is a megaflow with two heating elements (one operating via Economy 7). Whilst onsite I turned on both heating elements, before setting the timer as per clients request. The megaflow is 125 litres capacity - and I think heating elements where rated at 3kw. The client says that they are only getting 5-10 minutes of hot water before it runs out.

The timer is set for 4 hours overnight and then one hour top up during the day. Do I need to increase the number of hours to heat the water - or could there be another issue?

Thanks

 

[chrish_1977]

There might be an overload switch on the lower element, sounds like the economy 7 isn't kicking in, are the storage heaters ok? Once the main element is on you should get hot water within (I think) about 45 mins

 

[Ken77]

Thanks for swift reply. There are no storage heaters only boiler so difficult to know if the is just a problem with economy 7. I didn't see any signs of an overload switch on the lower element - then again I wasn't looking for one. Are these on the element?

 

[telectrix]

thermal cut-out, either on the heater or on the stat.

 

[Ken77]

Thats Telecrtrix. Is it likely that the cut out for the economy 7 would be seperate from that of the main element? The boost function controlling the main element seems to work to provide hot water?

 

[chrish_1977]

Doesn't sound like much point having e7 for just an immersion element, might be better off of it

 

[BrianDB9]

i'd test through the off peak side , there should be a resettable rod thermostat under the lid where the heater is.

Alternatively is there a switch before the timer that they are using and switching it off ? Its important for all switches to be clearly marked to avoid confusion youd be surprised how many immersion heaters are wired up with the off peak going to the top instead of the lower heater.

 

[SYKRAPS]

It could also be a faulty stat or a blown element, can you perform tests when the E7 is calling?

Can you post a photo of the stat?

 

[Spark1979]

Mega flow stats have a lovely hidden reset on the stat, once you know it's there it's always that!!

 

[Megavolt]

Is there a blending valve on the units outlet this could be the problem if the valves thermostat is faulty