Should you lag an economy 7 water heater?

Robin9

rosamy52 wrote: »

Well £10 is a lot of money for some of us, do you think I'm asking to much for the landlord to do it?

By all means ask the landlord but its you that pays the electricity bill - you may well get your £10 back in a few months.

Robin9

Robin9 wrote: »

the electricity bill - .

On the subject of bills - what tariff are you on and when did you last switch suppliers?

System

wavelets wrote: »

Should the tank be lagged/insulated?
Yes

It isn't.
It is.The insulation is below the outer metal skin you can see.

The booster immersion is not suitable for a bath. The booster immersion you can see as the upper heater on the side of the tank, so you can see how little water it heats. Immersion heaters only heat water above the heater itself.

Absolutely right. The OP has an unvented cylinder which by the look of it is properly insulated. The small white cylinder is the cylinder expansion vessel which is pressure charged. Two possible reasons for a shortage of hot water are a faulty heater/thermostat on the cylinder, or the thermostat has been set too low. I have a 250l unvented cylinder which heats for about 20 minutes in the morning and the same in the evening and we never run out of hot water. My cylinder stat is set at 60C.

It is difficult to tell from the photograph but it would be useful if the OP could confirm that there is no water flowing/dripping from the red Temperature Pressure Valve at the top of the cylinder into the tundish (The black plastic thing about a third of the way down the vertical copper pipe to the right of the two immersion heaters)?

Edit:

A further thought. Why was the pressure expansion vessel changed? Did the engineer correctly re-establish the air gap in the hot water cylinder - hence the question about water dripping into the plastic tundish. It is safe, and possible, for the homeowner to re-establish the air gap without calling out an engineer. The procedure is as follows:

1. Turn off the cold water stop tap.

2. Turn on the lowest hot water tap in the property and let it run.

3. Once hot water stops running, then go to the cylinder and turn and hold the red TPV at the top of the cylinder. There will be a lot of glugging and water will escape into the tundish. When the flow of water and glugging stop, then release the TPV. This process can take 10 to 15 minutes.

4. Leave the lowest hot tap open, and slowly turn on the cold water stopcock. Air will escape from the hot water tap. Close the hot tap once full flow has resumed. Sorted.

I usually recharge my unvented cylinder when I sense that hot water pressure has fallen. NOTE: if water continues to drip into the tundish after releasing the TPV, then you will need to call an engineer (see below)

Unvented Cylinder Fault Finding

http://www.advancedwater.co.uk/FAULT-GUIDE.html

Caution: Unvented cylinders are pressurised and engineers/plumbers must hold a G3 annotation before they are deemed competent to work on this type of system.

rosamy52

Thanks for replying and sorry to take a while to get back to you.

So they put in a thermostat rod last week to the big, main tank. The small tank was also replaced before that but that didn't solve the problem, I assume they adjusted the pressure gap thing you mention but I'm not sure - should I try soon what you suggest re that anyway or not? So then they got in an electrician who did the thermostat. There's no dripping water anywhere. But I’m wondering if the thermostat perhaps isn’t set very high or something? There’s no timer that I know of unless it’s under one of the two white dials which is where I think the thermostat/s are.

The tank is an ultra steel direct 120L by Kingspan. Not sure how old it is, I know the flats are about 12-15 years old but don’t know if this tank is that old. I think you’re right in that it’s internally insulated as it’s got a plastic feel outer, the pipes do feel hot to the touch. Would external lagging make any difference if I or the landlord did that after the temperature issue is resolved? Presumably a 120 litres should be more than enough for a bath?

I have had nice hot showers but not a hot bath which is why I was posting. I’ve had one in the evening which was rather pathetically luke warm and one in the morning first thing yesterday which was marginally better.

Thanks again, I appreciate yours and everyone else's help!

AndyPK

as you say it used to work, so you need to get the landlord to fix it.


I wouldn't spend money on lagging, particularly if you are short of money and its not your place.

rosamy52

I've been on NPower's standard Economy 7 tariff since moving in three months ago or so. I was on Bulb previously and would have swapped to them here but there made a massive mess with my final bill which has only just been sorted. It's on my to do list to do a comparison and swap if need be.

System

If you are happy that both immersion heaters are wired correctly and working, then someone needs to take a look at the temperature setting on the bottom (off peak) cylinder thermostat. The Kingspan installation guide for your cylinder shows that the thermostat can be set in the range 45 to 65C. This check can be done by any competent electrician. It is often the case that plumbers are good at pipework but find electrical wiring confusing!

AndyPK

If they are confused by wiring an immersion I would be very worried
with what combination they chose that hasn't worked!

Did they change the thermostat in the top one or bottom one, do you know?

rosamy52

I am not sure which thermostat it was, I should have made a note. What would be the effect of which thermostat was changed?

rosamy52

I don't know if it's all wired properly or not, I assume so as it is kind of working and nothing's exploded! It was an electrician who changed the thermostat but I don't know what he did with regards to the temperature settings.