Increasing hot water temp in Megaflo CL210 cylinder - safe ?

[swayzak]

Hello

We have an old megaflo - moved into the property summer last year.

Have had the airbubble recharged (once after moving in & just recently - however it is something I will attempt myself next time pressure drops / tundish drips as seems straightforward).

However the water temp is not terribly hot (I prefer hotter water) - seems to be set at around 50 degrees C on the indirect controller accessible from outside of tank.

I have now set to 55ish (as far as I can tell as not clear from knob where setting mark is !). I think I have turned the correct way as I turned one way until "click" heard, which I assume is the off position, then rotated other way until approx. 55 positioned at 9 o'clock (50 was there before).

Am I doing the right thing ? Will I cause any significant problems turning this up (apart from scolding !) ?

Thanks

 

[EAST61]

Generally unvented cylinders are set to 60c to prevent legionella build up

I'm unclear to how turning the temperature up will solve your problem though, as no-one has a shower at 50c as that would be rather painful

 

[swayzak]

If the water is stored at a higher temp, won't less have to be used when showering (as more cold will be mixed to bring temp down), thereby enabling more showers ?

Forgive the dimness ...

PS This is heated by immersion heater (on Eco7 at night), and not connected to the gas boiler central heating system.

 

[EAST61]

Well that's not what you said is it.

You didn't say you wanted more showers

You said you wanted hotter showers

 

[swayzak]

Well that's not what you said is it.

You didn't say you wanted more showers

You said you wanted hotter showers

Fair enough.

So this would eek out the stored hot water a bit further ?

And also are there any safety risks with this for the tank ?

 

[AdvanceHelpline]

Yes, you would get more "hot water" because you would be using less from the cylinder and more from the cold to mix it down. These units are protected against overheat so adjust as you feel suits you best.

 

[swayzak]

Any idea which way to turn indirect controller to increase temp ?

Thanks

 

[Daveydub]

Turn off electrical supplies to immersion heaters. Remove cap from lower immersion. Look for temperature control in here and turn up by 5 degrees. Replace cap. Re-instate electrics.

 

[swayzak]

Turn off electrical supplies to immersion heaters. Remove cap from lower immersion. Look for temperature control in here and turn up by 5 degrees. Replace cap. Re-instate electrics.

Thanks

Am I looking at the wrong controller then ?

 

[Lower]

It looks like the controller that you've uncovered is the temperature sender for a boiler. Nothing's wired to it.

The immersion element will have its own thermostat built into it so you'd adjust the water temperature as per Daveydub's post above.

 

[swayzak]

It looks like the controller that you've uncovered is the temperature sender for a boiler. Nothing's wired to it.

The immersion element will have its own thermostat built into it so you'd adjust the water temperature as per Daveydub's post above.

Thanks - that explains why the water was same temp this morning after adjustment !

If the lower device is immersion temp controller, what is the higher one ?

 

[swayzak]

PS Here is the lower immersion controller - it was set at 4 but I'm not sure what temp these values equate to. So I have increased to 4 1/2 & will check water temp tomorrow morning - is that sensible ?

 

[Lower]

Thanks - that explains why the water was same temp this morning after adjustment !

If the lower device is immersion temp controller, what is the higher one ?

You have two immersion heaters elements. You need to turn the temp up on the higher one too, assuming it is wired.

 

[JohnD]

as you're on ECO7, it's normal to have the upper element set to a temperature that will not come on unless the overnight cheap hot water has all been used up. The upper element is for daytime topups and costs about twice as much as the overnight rate.

Because hot water rises to the top of the cylinder, you might find you can achieve that even if top and bottom stats are about the same. But setting the top one hotter than the bottom one would be uneconomical.

p.s.
take a look at your electricity meter to make sure the lower element is heating up at night on the cheap rate. And verify that the upper element still works. You will have to do that when the cylinder has used up all its hot water. If the elements are modern, they will have an overheat cutout, and it is possible for the top one to trip because the lower element has made the cylinder very hot. The modern overheat cutout does not automatically reset when the cylinder cools down, it is a secondary safety device.
edit:
on yours, it's the button marked "safety." I don't recognise the brand but it will probably pop out when overheated and need to be manually pushed in. If it pops out something is wrong.

It's strange that your water is not hot enough with the stat turned up to 4. So verify the lower element is actually switched on, and draws 3kW at night. It could have failed or been turned off.

 

[D_Hailsham]

The manual says:

It is recommended that the immersion heater thermostats are set to between position 4
and 5 (60C - 65C), however they can be set between 1 and 5 (10C and 70C).

So you should be OK with is where it is in the pic.

There are two immersion heaters the lower one heats the whole cylinder, the upper one just the top part. The lower one is normally controlled by a time switch so it only comes on at night when electricity is cheaper (if you are on the Economy 7 tariff). The upper thermostat is used during the day to "top up" the cylinder, if necessary.

This begs the question: why are you heating the cylinder by electricity when it can, normally, be heated more economically by the boiler?