Direct Electric Hot Water Tank

[Les Ponts]

Downsized to a smaller house which has an Elson Opal direct fed water tank which worked well for a while but then didn't heat the water but a day later it worked. Then stopped altogether. Various electrical items were tested and the element(only one at the bottom) was replaced. It worked well for 3 days and once again no hot water. The timer is okay and the current to the element is okay both Economy 7 and the boost. Could an element go after 3 days, is that likely to be the problem and should I take the element back to Screwfix? Les

 

[JohnD]

it's unlikely but not impossible. Your fault pattern was the same before the element was changed and after. This (and the pattern) suggests to me that the element was not the cause. There is very little electrical in a direct cylinder to go wrong.

A poor connection somewhere on the wiring seems more likely to me. A competent electrician can test the thermostat and the element for continuity, switching and correct resistance (or you could do it if you have a multimeter) and can look at the connections in the switch and elsewhere.

I would be inclined to bypass the timer and use simple switches for a few days in case there is an intermittent fault in the timer. I might also connect a lamp to the E7 circuit so I could see if it was switching on and off at the correct times, and that the times corresponded with your own timer.

No doubt a new thermostat was fitted with the new element, and the overheat breaker has not tripped.

 

[EFLImpudence]

Could an element go after 3 days, is that likely to be the problem and should I take the element back to Screwfix? Les

Yes, had one last an hour once.

Best make sure, though.

 

[Les Ponts]

Many thanks for your response. I am sure my electrician has done most of what you mentioned but I will pass your suggestions on.

 

[Les Ponts]

Downsized to a smaller house which has an Elson Opal direct fed water tank which worked well for a while but then didn't heat the water but a day later it worked. Then stopped altogether. Various electrical items were tested and the element(only one at the bottom) was replaced. It worked well for 3 days and once again no hot water. The timer is okay and the current to the element is okay both Economy 7 and the boost. Could an element go after 3 days, is that likely to be the problem and should I take the element back to Screwfix? Les

 

[Les Ponts]

Enjoying the smaller house but still having problems with the hot water tank - no hot water - I have checked all likely causes but no solution. Could it be another immersion element or a new hot water tank! Any ideas?

 

[ericmark]

To work then stop then work again I would look at items doing the switching on/off. Could be thermostat, timer, or main Economy 7 contactor, but poor connection will likely get very hot and fail, but a set of contacts may simply not make some times but make others.

The tank can get full of rubbish, however one would hope that was checked before renewing the element, but in the main the rubbish would just need removing, should not need a new tank.

There are two types of element, those which go into the side of the tank, normally two, and those which go in the top, normally two elements in one unit, the short element connects to boost, the long one to economy 7 and of course two pockets for the thermostats or twin thermostat idea is in all cases the economy 7 is set hotter so even if boost is left on, the short element is only used when tank has cooled down.

With this twin system it seems unlikely both elements would fail, so I would be looking at the control module which selects which element to use, I would guess you have some thing like this

That is what I would be looking at to see if there is a fault.

 

[Les Ponts]

To work then stop then work again I would look at items doing the switching on/off. Could be thermostat, timer, or main Economy 7 contactor, but poor connection will likely get very hot and fail, but a set of contacts may simply not make some times but make others.

The tank can get full of rubbish, however one would hope that was checked before renewing the element, but in the main the rubbish would just need removing, should not need a new tank.

There are two types of element, those which go into the side of the tank, normally two, and those which go in the top, normally two elements in one unit, the short element connects to boost, the long one to economy 7 and of course two pockets for the thermostats or twin thermostat idea is in all cases the economy 7 is set hotter so even if boost is left on, the short element is only used when tank has cooled down.

With this twin system it seems unlikely both elements would fail, so I would be looking at the control module which selects which element to use, I would guess you have some thing like this

That is what I would be looking at to see if there is a fault.[/QUOT

 

[Les Ponts]

Many thanks Ericmark. My electrician is on holiday hence my questions but I will pass all this on. However, I live in a hard water area and although noticed sludge in the bottom of the tank I didn't clean it out! A point I will remember if the element needs changing again (but how do you get it out?). My tank is an old Elson Opal and the element is on the front side near the bottom, I replaced the old one with an 11" Titanium type from Screwfix. That said, near the top again on the facing side of the tank there is a capped aperture but not sure why? We replaced the timer and reset it for 2 hours on Economy 7 during the cheaper hours which worked well. Summer heat arrived and we switched off the timer unit and have only been using the boost, either 1 or 2 hours, now and again until recently then nothing. Luckily, we have an independently heated Mira power shower unit on the ground floor! The lady of the house loves her bath.