have I wired our new duel immersion hot tank correctly?

minmax89

Hi there.

I replaced our hot water cylinder for a modern insulated one around 6 months ago. The new one is about 140cm in height and 18" dia. It has two seperate elements that are about 1ft long. They go in the tank horizintally - one at the top of the tank and the other at the bottom. I wired them in by wiring the top element to come on when the 'sink' switch is on, and the bottom element comes on with the 'bath' switch on.

Problem is the water is just nowhere near as hot as when I heat the tank indirectly via the boiler/central heating coil in the tank.

Have I wired the two elements wrong? Should both elements be coming on when the 'bath' switch is on? If so, should I then loop the top element to the bottom one? (when one element is on the elecricity meter is going 90 - I dread to think what it would be like with the two on and can't imagine it being cheaper than having the gas boiler heating the tank of water)!!!

Any help is much needed as I'm heating my water everyday by having the heating on for an hour in the morning and in this glorious summer we're having, it's a nightmare!

Many thanks
Adam

Doodoo

Each element should be seperate (not looped). Sounds like its connected correctly. Have you checked if the internal temp stats are set correctly?

davelerave

sink-top. bath- bottom .is fine if they're wired properly and working .they can't run simultaneous without 2 supplies .you can fit a horstman/economy 7 type control if you happen to have nightsaver/ dual-tarriff.you can also look at the zoning on the heating system.is DHW zoned separate on your heating system?.there's been a few questions on this lately

minmax89

Thanks for the replys. The first thing I checked was the temp/thermostat in the two elements and they're at 60 so they're fine.

Is the nightsave/dual tarrif thing something I would have on my ESB (now Bord Gas) account? If so, I don't think I do. I'll check when I get home...

So they're wired in correctly it seems. I'm not 100% sure what you mean by 'zoned' Domestic Hot Water. The CH system is seperate from the DHW. The CH comes from the boiler, goes through the inverter coil in the hot tank, down through the radiators and then back to the boiler. The hot water comes out the top, through a 3-bar pump on the floor, down to the bathroom, and then splits off to the kitchen sink.

I had the intention of fitting a motorized valve to the radiator branch, connect that to a 2-channel digital timer (I currently have a analogue clock to the boiler) and have that heat just the tank of water and go back to the boiler.

But the guy in Chadwicks says The immersion (for doing the same job) would be cheaper to run than the gas boiler.

The immersion was only going to be a back up/secondary solution but I really should get it to work right before going the other route, yes?

Many, many thanks!

davelerave

the 'DHW zone' is the CH loop through the cylinder coil.the simplest way to heat the water if it's separate to rads.if you had dual tarriff you would have two separate rates on the bill for day/nite.you prob don't have it.

minmax89

so just to clarify Davelerave, if I eventually get the immersion sorted and i fit a motorised valve on the pipe after the coil but before the radiators and connect that to a timer I'll be economically better off using the gas boiler and keeping the immersion for emergency back up?

davelerave

normally a plumber will fit the valve/s and tell the sparkie how the system will operate if it's non-standard or whatever.the plumbing can vary so it's hard to be specific about location of valves.there's an electrical drawing for a standard(or basic) 3-channel system in the diagrams section

Randyleprechaun