Water won't heat up in cylinder though immersion & stat seem fine

[Connor Williams]

Hello guys, I am having problems with a cylinder in a flat that is failing to supply hot water at the taps.

The top element or (top up) was renewed three years ago, yet even when both elements are turned on, the water will not heat up.

Both immersion elements and both stats have tested okay for continuity and there is 230 volts present at the terminals. Both elements make a hissing noise when plugged in yet even after several hours the water is only very slightly warm.

I have been informed it could be heavy scaling inside the cylinder that is stopping the water from heating, the cylinder is 20 years old so should I just take the plunge and buy a new one?

Any help would be greatly appreciated!

All the best,
Connor

 

[jtsplumbing]

You could still have faulty heaters that are only part working, I used to live in a hard water area and heaters only lasted 18 mths, Whay not replace the heaters first B4 changeing the cylinder ! Do you know how much a econ 7 cylinder is ??
When you remove the heaters clean out any scale from bottom of cylinder, fit a 14" heater in bottom of tank and go for a better quality one. Used to do a hairdressers every year and get at least 2 buckets of scale out of cylinder (Marlow area)

 

[BLOD]

try testing the resistance of the immersion element with a multimeter, (18 to 20 ohms is good) also test for continuity from the element terminals to earth.

 

[chris watkins]

20 years of electrical heating water (if a hard water area) it's time to buy a new one & think yourself very lucky it's last that long.
You could ask a plumber to remove the bottom one & try to descale but it is likely to be a can of worms.

 

[Connor Williams]

Thanks for the help guys, I will drain off the cylinder and replace the element first, as they are £17 each as opposed to £209 for a new cylinder! Worth a try, many thanks

 

[jtsplumbing]

That seams a low price for a twin eliment cylinder what size is it ??

 

[Centralheatking]

While your drained down undo the top nut on cylinder - ie hot water feed lift and push to one side. Then
examine the inside of the fitting. Often they can be really rocked up - restricting the flow. If so
get a masonry bit on lecky drill and carfully open up the hole. Have seen this so restricted as
not able to push electrical screwdriver past but still supplying water.

centralheatking

 

[AWheating]

dont buy a standard copper immersion heater, get either a nickel alloy type or even better a Titanium for hard water areas.

http://www.heatraesadia.com/docs/Immersion_Heaters_-_Issue_4.pdf

 

[jtsplumbing]

Still want to know where he is getting a twin element econ 7 cylinder for £209.00 ??

 

[mountainman]

Could be plus vat.
Or here
[DLMURL]http://google.com/products?q=Gledhill[/DLMURL] Economy 7 Direct EnviroFoam 900mm x 450mm Cylinder&offerid=2382795273370650302&source=shopper

 

[Connor Williams]

Thanks for all your help guys, in conclusion: I drained the cylinder and yes the lower element was totally limescaled up and barely working, (a resistance test would've told me this as I only tested for continuity on the stat and element. For the record you touch the live and neutral of the element with the multimeter set to 200ohms and the reading should've been approx 18ohms am I correct?!)

Anyway, renewed the element and stat and the water is banging hot.

As for the cylinder price, go to Diamonds builders in brixton and they were selling a cylinder 1200 x 450mm for £209, immersions £17 each, luckily it didnt come to that.

All the best guys

 

[Dotty]

Thanks for letting us know how you got on Connor. It seldom happens. Glad you're sorted.