Dimplex cylinder

[Whn1]

Hello my favourite people!

Ok dimplex pressurised cylind (similar to megaflow)
the cylinder is direct, in a newish build flat.
130ltr has two immersions, when you switch both both immersions on the water gets hot as it should but the cylinder loses heat very quickly, like if you have a shower the water will be cold again in 4minutes ( no chance of a bath), also if you leave the immersions on continuously it doesn't stay hot.
The homeowner has had the plumber out and the electrician who both claimed to have fixed it but quite clearly didn't know what they were doing or how the system works, the rads are electric and run off a programmer.

Phone this kinda makes sense, thanks guys.

Tony

 

[shaky]

May be faulty immersions mate I had one the other day were the element was touching the stat pocket so it was getting the water hot but not a full tank as it was cutting out to quick ether bend the element out a bit or change it. I changed it and all was good.

 

[Whn1]

But both elements? Also is there a difference between the top and bottom immersion?

Excuse the silly Q's I don't usually deal with these elec systems.. Not a fan

 

[shaky]

No difference mate you will not be able to have both on at the same time the bottom one will come on at night usually around 1am till 8am and the top one as a boost it may be on one the stats faulty and the other elements touching check the cut out on both stat and make sure nothing has tripped if not drain the cylinder get them out and have a look. Hope this helps mate.

 

[Howsie]

No reason why elements can't run at the same time. Depends on how it's been wired/set up.

Silly question but is it plumbed right?

 

[Whn1]

No reason why elements can't run at the same time. Depends on how it's been wired/set up.

Silly question but is it plumbed right?

Yea plumbing is sound, not much to it as its direct, both immersions are just wired to spurs.

 

[markfxy]

the bottom one will be economy 7 it sounds like this ones not working if its just relying on the top immersion then the volume of hot water will be reduced and could easily be used up with one shower

 

[tamz]

Cylinders with 2 immersions are usually wired with one (the bottom one) to off peak. It is unusual to have both wired to standard tarriff.
The bottom element comes on at off peak times (times depend on what plan) and heat the full tank. The top element is meant for a back up during the day if you run out and gives under half a tank (or there about) of water. Sounds like only the top half is being het.
Easily checked with a multimeter or even a neon screwdriver. Take the cover off the elements and test them.

 

[Whn1]

Ok tam is this easy enough to check? Do I just check the immersion has 240v to the live or is there a switch I can check after the stat?

Excuse the wording, never had to check one before..

 

[jtsplumbing]

Tip if your going to replace bottom heater use a 14" one instead of the 11" are you in a hard water area ??.