No hot water from hwsc

[rocketmanbkk]

Chaps

a woman called me and has no hot water. Shes a lovely lady and I replaced her electric shower, toilet inlet, toilet siphon etc. so a good customer.

She is in a flat, all electric.

The airing cupboard has the tank but i've never changed or diagnosed anything to do with immersions etc.

So, my question is, if the tank has one immersion at the top, should I just try to change the thermostat rather than the whole unit?

If it's got 2 immersions, how do you know which ones broken?

Also, if its just a top one, i take it that if i do need to change the whole lot I dont need to drain the whole tank?

Talking of draining, its a 2md fllor flat so is it better to isolate water and turn hot taps on and have a cuppa?

Cheers all

Rocket

btw, another successful siphon change today!

 

[Whn1]

You can check the switch live on the stat to see if its switching or you can test the immersion itself, you should be getting around 20ohms if its good.

 

[Toxic Ted]

If you try to drain a direct hot water cylinder in a flat then you wont do it by opening the hot tap. DHW Cylinders fill from the bottom and feed from the top so you physically cannot drain without a hose on the drain cock to a low point eg.shower tray.

Using a multimeter, check continuety through the stats( power off obviously) which will tell you if and which stat has failed and dont forget to check the obvious like MCB breaker is hasnt tripped and if it has power to it when switched.

If you need help PM me your mobile no and ill sort something out.

 

[rocketmanbkk]

Ok, customer told me she has 2 immersions, bottom one works so its top one that's faulty. Means if needed dont need to drain whole cistern!

Hopefully just thermostat that will sort it!

Thanks for your reply.

Rocket

 

[leelister6]

Done quite a few of these and the drain cocks hardly ever work. I ended up isolating cold feed, opening all hot taps and when the water stops flowing from the taps, disconnecting the hot water outlet, shoving a hose to the bottom of the cylinder and syphoning the water into the bath or out the window. Oh, and I can guarantee you that the tool that put the immersions in slarted boss white all down the threads!

 

[stoker122]

If you've drained the cylinder I would change both immersions as the other is likely to fail as well soon.

 

[kay-jay]

A simple voltage tester can ascertain whether the stat or the element has failed.
No great electrical knowhow required.
Simply touch one point to earth connection and one to the live at one side of the stat with demand on and then keeping the connection with earth touch the other side of the stat which is also live. If the tester lights up both times then the element is gone. If the tester lights up only on one then its the stat