Safe to keep boiler off?

ianbeale_steeplecocque

I moved into a flat last year, and it has a combi boiler. I live alone and have had the heating on for maybe 6 hours in the 8 months I've lived here. My gas bill shows my usage compared to the estimate for the year, and even without the heating on, it's probably above the summer estimate.


The boiler comes on probably every 15-20 minutes, I think just to keep some hot water ready when needed, but the main radiator also sometimes gets really warm when this happens, or when I run the taps.


I don't know how much gas this uses, but is there any harm in only switching the boiler on when I need hot water? I have a light-switch type switch by the boiler so lately I've just been turning it off until I need a shower or to wash up.

mmmmikey

Hi - yes, this is potentially harmful and you should really turn the boiler off by the switch on the boiler, not by the mains power. This is because in many boilers there is a cool-down process that runs fans etc. to shut the boiler down cleanly and safely after you turn the power off at the boiler. This won't work if you kill the power at the mains. A radiator coming on with the hot water points to a problem with a diverter valve so I would suggest getting the boiler checked out by a gas safe engineer.

The_Fat_Controller

Even with the boiler in hot water pre-heat mode, 20 minutes cycling suggests there may be a problem with a sensor or you have the water temperature set very high.

Can you disable that mode ?

As said above, it sounds as if your diverter valve is knackered.

Combi boilers have a pump over-run timer, which dissipates the heat, so never turn it off until it is silent.

Even then, most electronics are best left on, a lot of faults occur on powering up cold devices.

[Deleted User]

1. get a gas safe engineer out
2. never just turn if off at the wall
3. look for the manual for your combi boiler online. Mine has a button marked ECO on the water side of the control panel. When that button is lit, the water will not be preheated.

[Deleted User]

For the last two years I have switched my 5 year old boiler off at the main switch next to the boiler..all seems ok, apart from a constant small loss of pressure which I can t find the cause of , but after the above info I will now switch the appliance heating off at the boiler facia leaving the hot water call for button to being switched on.

macman

Another vote for a faulty diverter valve. Unless the combi has a pre-heat function, which most don't have: make and model please?

ianbeale_steeplecocque

macman wrote: »

Another vote for a faulty diverter valve. Unless the combi has a pre-heat function, which most don't have: make and model please?

It's an Ideal Isar.


I'm not sure if it's every 20 minutes that it fires up, it's just a guess but it seems like a few times an hour.

PennineAcute

I have my combi set to come on every now and then. It is the only that I get get hot water, without having to run the tap for a few minutes.

Just wondering if your combi is similar?

ianbeale_steeplecocque

That's what I thought was happening, that it keeps some hot water on standby so the taps run hotter quicker.


The only problem is the radiators getting slightly warm when this happens, and warmer still when I run the hot water for a while (ie showers). I even have to turn off the thermostats on all the radiators that have them, otherwise the whole flat heats up when I have a shower.

Mister_G

ianbeale_steeplecocque wrote: »

That's what I thought was happening, that it keeps some hot water on standby so the taps run hotter quicker.


The only problem is the radiators getting slightly warm when this happens, and warmer still when I run the hot water for a while (ie showers). I even have to turn off the thermostats on all the radiators that have them, otherwise the whole flat heats up when I have a shower.

Looking more and more like the diverter valve.