immersion heater

[lee mcgregor]

lads advice would be welcome. i was called out to a job today and on finishing the job the lady ask me to look at the immersion as they were only ever getting warm water , i took ohms of element which work out correct and check thermostat which was broken (consistently staying on ) now disconnected link from element to neutral to see if same voltage in and out which again both 239 v so that was ok. any other ideas to why the water only ever warm when really should be scalding hot since thermo was constant on???????? water flowing ok to so dont think any blockages? cheersApplaud Smiley

 

[kme]

Unless the pipework involves a TMV mixer (looks like a 3 port valve) ; not usual on imm. tanks. If there, that would limit temp. at taps by mixing hot with cold to provide temp specified by TMV (any old `uns lived there???)

The only other option I can think of would be strange thermostat wiring, involving the tank stat (if there is one?) feeding the supply to the imm. via a relay? Would be an odd system, but not unheard of.

Is the tank itself getting hot; or just warm?

Erm..... Another thought occurs. If they`ve only got a 7" or 9" imm. in the tank, that could cause the problem........

HTH

KME

 

[lee mcgregor]

wiki.diyfaq.org.uk/index.php?title=Immersion_Heaters

found this very helpful thanks for reply

 

[a1]

http://wiki.diyfaq.org.uk/index.php?title=Immersion_Heaters

 

[Barx]

I usually find this is caused by lime build up in tank combined with a short element. Thus the element heats up the 'wall' of lime and not soo much the water.

 

[Evans Electric]

Only just seen this one . I tend not to rely on res.reading on immersions , if they are backed up by a rewirable fuse and no RCD they tend not to blow. Heaters will split open in the water and even just two prongs, the rest having dropped off, still working but not very hot. Megger it to earth and /or try your clamp meter to see if the current matches the killowatts. Luke warm water usually means duff heater.

 

[baldelectrician]

Had this with a duff element. Not in bits, but break in the element inside that made open circuit when the water heated up, and closed again when the water cooled down

A new element fixed it.