Immersion question

MarrowFarmer

Have got a slight gas problem at the moment resulting in no gas for the next week or so, luckily the hot water tank has an immersion heater for such emergencies. We have 2 showers running of 1 pump so our water usage is quite high (2 normal showers or 1 very long shower will empty the tank). Apparantly our immersion has no thermostat on it so we have been advised not to leave in on for too long. My question is how long should an immersion heater take to heat a tank of water! I know I haven't supplied any figures, mainly because I don't know them but it looks a pretty standard sized water tank so rough times appreciated.

grahamc2003

Sheesh - i'd say get someone round to check it out - sounds a right dangerous bodge somewhere. I wouldn't turn it on at all, just in case you forget to turn it off when it's hot.

MarrowFarmer

Yeah did sound a bit odd, lived there for 6 years and knew nothing of said heater . It's just a switch on the wall right at the back of the airing cupboard. It seems to be working mind and if it ties us over for a few days then I'm happy.

GlynD

Can't understand why there is no thermostat on it. Maybe it's one of those things you can address now for the future? It isn't rocket science for a good plumber to fit one of those.

MarrowFarmer

The house is about 13 years old and I'm pretty sure the GCH is standard install for all the houses round here so I can only assume it is there for emergency use only (like now) but it does seem odd to have no thermostat, will get one stuck on just in case someone mashes the switch in future. In the mean time though anyone know how long it should take to heat the water?

robert2012

The thermostat should be on the end of immersion heater sticking out of the tank.

Or are you thinking you should have a separate thermostat that you can alter where the on/off switch is situated?

Cardew

You cannot buy an immersion heater without a thermostat; they are integrated with the heater. Take the cap off the immersion heater and you can adjust to the temperature you want. see
http://www.diydata.com/problem/immersion/immersion_adjustment.php

Are you thinking of a 'tank thermostat' that straps onto the tank and controls the temperature of the water supplied by the gas boiler? Some CH systems don't have these and the water heats to the temperature set on the gas boiler.

If your your immersion heater thermostat is faulty you will hear the water bubbling as the water boils(or no heat at all)

MarrowFarmer

Ok I don't think I'm thinking anything I was mearly saying what the gasman told the wife when he shut of our gas supply.

We are on a gas boiler for our water, CH, Hob and fire. We currently have no gas. Gas man informs us we have an immersion heater for emegency use but to be careful as it has no thermostat so we musn't forget about it. I simply asked how long should I expect it to take to heat up a full tank of cold water.

I take on board all the thermostat comments and will speak to the chap who is sorting our gas out next week but for now does anyone fancy answering my original question?

Cardew

MarrowFarmer wrote: »

Ok I don't think I'm thinking anything I was mearly saying what the gasman told the wife when he shut of our gas supply.

We are on a gas boiler for our water, CH, Hob and fire. We currently have no gas. Gas man informs us we have an immersion heater for emegency use but to be careful as it has no thermostat so we musn't forget about it. I simply asked how long should I expect it to take to heat up a full tank of cold water.

I take on board all the thermostat comments and will speak to the chap who is sorting our gas out next week but for now does anyone fancy answering my original question?

Supplementary question - how big is your tank!!!!

Assuming you have a 3kW immersion heater try 90 minutes.

Bear in mind when using a shower that you may have to ajust the temperature from where you have it when the tank was heated by gas CH

MarrowFarmer

Cardew wrote: »

Supplementary question - how big is your tank!!!!

Assuming you have a 3kW immersion heater try 90 minutes.

Bear in mind when using a shower that you may have to ajust the temperature from where you have it when the tank was heated by gas CH

Thankyou :beer:
Sorry I can't answer you supplementary question but it looks the same size as every other hot water tank I've had

Snow_Dog

Just been through a similar situation, major overhaul of CH so relying on immersion for a week to warm up HW tank. If its a standard immersion heater, (you can see a silver, round box about 4 inches in diameter sticking out the top of the hot water tank), then odds are it does have a thermostat.

The heating time will totally depend on the immersion heater (what wattage it is). Best thing to do is go on trial and error, stick it on 1/2 hour before wanting a shower and see how long it lasts, you will have a bit of notice before the water runs cold. Just be aware when showering it might run out. You can feel the top of the tank where the pipe comes out whether the top of the tank is warm enough before you start your shower.

Also its a good idea to warm up the water after showering as if you only have a 1/4 tank of hot water left and you have just introduced 3/4 tank of cold you will lose the remaining hot during the day.

Sorry its not more specific on timings but there are so many variables, not just immersion power but tank temperature when you start will ake a big difference.

We were putting the immsersion on 30 mins before showering the other week and it was fine.

Leaving it on 20-30 mins afterwards to reheat the water.