Immersion Element Replacement Query

gillamandango

Hey All, looking for some advice. Mothers house who has mobility issues and all the plumbers I called either won't do it or don't answer. Appreciate it that's its the time of year, and I am in rural Ireland, but I need to get it sorted ASAP so will have to go at it myself. I can turn off all the electrics so that won't be an issue and know the pitfalls of warping the tank when cracking the element, then potential leaks, but no other choice unfortunately. So I have a few questions and appreciate any input. Pics will probably show more issues but I can address those too.

Firstly, any way to isolate the cylinder out of the CH loop? I would like to get the heating on, been off 2 days looking for plumbers, but all I see is a cold water input valve on the top left, no clue what the bottom left or top right valves do. Pipes from them run from Basement where boiler is, to attic. I see there are 5 pipes running to attic, middle one is the vent I assume. I have tried figuring out what all the pipework is for but am clueless. I know they added more rads so that could be what the stainless pipework is, but would be guessing.

I am going off getting parts but would initially love to know if I can isolate the tank so I can get the heat back on.

I assume then its just, turn off the cold input, drain the hot taps, isolate the electricity, drain the cylinder a bit, crack the element seal, drain it more, replace element, top up tank, check for leaks, and rewire element, wait 20 when back on, check for more leaks.

gillamandango

Shopping list?

Wearb

You shouldn't have needed to turn off heating at any time. Just isolate the domestic hot water supply to the cylinder and open a hot tap on the same floor to help with the heated water expansion when the coil heats it up. You probably have a valve on the coil also, but seeing as you are fixing it today, I'd leave that alone.

10-10-20

Yeah, as Wearb is saying, the tank element is in the domestic hot water compartment of the tank and the coils from the heating system are separated from that, so there is no need to isolate out the CH when replacing the element.

It looks to me like you might have a train/tap for the cylinder at the bottom left of the image there? All you need to do is take off around 20l of water, or so. Then try tapping out that element. I did it and buckled the tank on a 25 year old system once, it can really be a pain, but yours looks to be 10 or so - might come out easier.

Good luck, we're here plugging for ya! 🎅

carveone

James from plumberparts has a nice little video on doing this which might help. He's entertaining at least.

https://m.youtube.com/watch?v=mZ2MT0SKVZY

He says the same as 10-10-20 is saying but to crack the immersion slightly before draining. You're less likely to buckle the tank if it's full as copper tanks are awful thin.

gillamandango

Thanks for all the responses. In typical Screwfix ways, can't collect until the morning so more time to figure out their system.

There is that valve on the coil in the pic, on the flow that I can shut off. Thanks for suggestion.

I shut off the cold supply to the cylinder, but out of interest, if I run the CH with the faulty immersion seal (even with hot tap open as suggested, would I be prone to pressure and more leaks from the immersion seal while the CH is heating the cylinder?

Drain valve is on bottom left so that's easy access thankfully for the morning.

Any ideas what the other 2 valves are for? The left one (Bottom) seem stuck solid in whatever position it is in. The other then on the right can be closed. I wonder is this the New Rad supply from the boiler, but why would it be going to the attic?

Wearb

" if I run the CH with the faulty immersion seal (even with hot tap open as suggested, would I be prone to pressure and more leaks from the immersion seal while the CH is heating the cylinder?"

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Not from any extra pressure. The thermal expansion might work in your favour or against you. It won't matter much anyway because with the water not being replaced, it'll stop soon anyway.

monseiur

Not exactly answering your question but if the oil boiler is heating your domestic water also, why not postpone replacing the immersion element till after Christmas in case of leaks etc. Plumbers will be off from tomorrow, hardware stores will be closed etc.

To help crack the old immersion it may help to heat it gently with a blow torch.

gillamandango

Got lucky, opened by hand force. No leaks. Still no clue how that setup works but we have heat and hot water.

Two things I noticed - there seems to actually be no flow/return coil from the boiler, at least no pipes got warm when I ran the boiler after the install. Only coil seems to be from the Solar panels.

Secondly and this thew me for half hour, power everywhere, all the right places, right voltage, etc - no hissing noise from element heating up. 1hour later, still no noise but hot water in the taps. I got the wrong element, thought it was a dual but put it in anyways as the immersion isn't used that much.