Boiler & tank on/off during holiday???

bsod

alderpoint wrote: »

The OP said it is new build.


Even our 20-year old system has about 3" of factory-applied insulation on the tank and the boiler (non-condensing) hasn't got a pilot light.

nope, they said it was a new build area, it was obvious before any details were forthcoming, that it wasn't new at all because all the neighbours were apparently springing leaks out of every orifice and the op was going to replace the system.

The requirement for boilers to be condensing happened in 2005, they still cost pounds to run. The fact yours is 20 yrs old and doesn't have a pilot light is irrelevant, (the only thing known about the op's boiler is the brand), and it still costs pounds rather than pennies to leave a boiler to heat up water for a week whilst you go on holiday.

You may want to take a tape measure to your insulation, because 3" of insulation wasn't a requirement 20 years ago, 10 years ago, or now

wildesavings wrote: »

The boiler is a potterton and the tank a boilermate 2000. Both 10 years old like the house

10 years, in case you didn't know, is a decade old system.

This is in the shops in 2015

http://www.screwfix.com/p/rm-indirect-copper-cylinder-1050-x-450mm/40082

25mm standard insulation and large heating coil. Complies with Part L Building Regulations.

Before any details of the OP's system were made available, Cardew and others decided for some reason to challenge the statement that it costs pounds rather than pennies to run a boiler and pump to maintain a cyclinder of hot water for a week.

If you're going to join in with this pointless argument by repeating the words new build like a parrot, perhaps you might want to read the thread properly beforehand and post some actual numbers to backup your statement.

Quoting some theory doesn't cut the mustard, answers are proven with experiments. Anyone who drives a car will have noticed it doesn't get anywhere near the quoted mpg, anyone who owns a freezer/fridge/tv and a power meter will have noticed they also don't get anywhere near their quoted power usage unless you use them in an abnormal fashion, the regs mean very little once something leaves the factory and enters the real world.

Even if the insulation is as perfect as is claimed, the 56p a week figure takes no account of other losses in the system or the cost of boiling it in the first place.

r2015

33kwh to heat and then maintain a tankfull of water at 60 degrees for 168 hours with nothing but an inch of insulation is on the optimistic side, a pilot light alone can use 23kwh/week, there are plenty of those still about

My previous hot water system was similar.

Pilot light used 3 kWh a day, if I didn't use any hot water gas consumption was 5 kWh a day, (I went away for a day and stayed a week that's how I know and had read the meter that morning)

When I went on holiday I used to turn the gas off at the meter and it used about 32 kWh to heat the tank back up.

So I worked out that leaving the gas and pilot light on was just as economical as turning it off if I went away for a week or less.

Now I have a combi and if I don't use hot water I don't use gas.

bsod

illogical. that's like the old myth that's it's cheaper to leave the heating on 24/7

how can leaving a pilot light and boiler running for a week be cheaper than turning it off.

r2015

illogical. that's like the old myth that's it's cheaper to leave the heating on 24/7

how can leaving a pilot light and boiler running for a week be cheaper than turning it off.

I know but:-

Cost to keep tank of water at temperature of 60 deg C for one week = 35kWh times unit cost.

Cost to heat tank of water from ambient temperature to 60 deg C = 35 kWh times unit cost.

Same cost.
Of course after 7 days it is no longer economical as cost to heat water up is still the same but there is the 5kWh extra per day.

r2015

that's like the old myth that's it's cheaper to leave the heating on 24/7

I used to do that and never used any more gas.

I used the same gas in 24 hours as I used in keeping the heating on from 7:30 to midnight as the amount of gas used to heat the house from 10 deg C to 22 deg C was the same as what was used to maintain the temperature for the hours the heating was off.

bsod

Same here, in summer

wildesavings

Thanks for the replies everyone. Seems the parts required to get the boiler back in the land of the living are £500. So we're looking to replace both the boiler AND the tank in the next 2 weeks - I hate to think how much boiling the kettle for everything is costing us

Does anyone know about replacement systems? We've been advise that switching to an 'unvented' system instead of the tank is the best option but we're clueless. Googling everything in the hope of not been taken for a ride.....

Cardew

r2015 wrote: »

I used to do that and never used any more gas.
.

Yet another property to which the laws of physics don't apply!


If I understand you correctly, you use the same amount of gas with the heating on 24/7 as having the heating off for a few hours in the day?


So what if the heating was off, say, 23 hours?


What if the heating was off for a week? Would it still be cheaper to keep the heating on 24/7.


What if the heating was off for a month, a year, 2 years?


At what point(i.e. amount of time the heating is off) do the laws of physics not apply?

r2015

If I understand you correctly, you use the same amount of gas with the heating on 24/7 as having the heating off for a few hours in the day?

No, for a few hours at night when the outside temperature was -20 deg C. It gets cold in Scotland.

That was with my old warm air heating.

I have a new combi boiler and radiators now so I won't know until the winter if that still applies.

So what if the heating was off, say, 23 hours?

So what?

It was off for 8 hours not 23 hours.

At what point(i.e. amount of time the heating is off) do the laws of physics not apply?

8 hours?