Gas boiler pilot lights using ~550W!

Robin9

OP Are you saying that your GAS meter advanced by 50 units over a 9 period - you don't give a period but 4475/550 - and 1 dialled unit is approx 11kwh ?

Or is the 550kwh your ELECTRIC reading ?

esuhl

Wow! Thanks for all the responses! :T

Cardew wrote: »

4575kWh/year is 12.5kWh a day; so I assume you are stating the pilot light is using 0.55kWh every hour?

There are several threads on pilot light consumption if you do a search and some of the figures are very high - but iirc none as high as 12.5 kWh a day

Yes -- 550W is the same as 0.55kW or 0.55kWh/h. I thought it seemed a bit high!

Owain_Moneysaver wrote: »

Something must be heating the hot water ... electric immersion?

Nope. We have an immersion heater, but that's off and the timer isn't set. It can only be the pilot light from the boiler... :-/

penrhyn wrote: »

Perhaps a check on the Electric meter readings is in order here?

Hmmm... Perhaps, but I'm pretty sure the water isn't being heated electrically. And, unlike gas which should have virtually zero usage when I'm not heating air/water, I'm not sure I'd spot an anomaly in electric energy consumption since it varies quite a bit anyway... But I'll start taking readings too in case it helps...

Robin9 wrote: »

And the gas readings - if the boiler is only producing hot water and no central heating at this time of year consumption should be quite low.

It shouldn't even be producing hot water! There's definitely no warm air (thank goodness!), but the water seems permanently warm. The boiler isn't "firing up", so I wondered if it was just "ticking over" using the heat from the pilot light to heat the water...?

brewerdave wrote: »

Suggestion -have you got a frost stat on your boiler? If so, it might be faulty so that the boiler is actually cutting in and heating water when you think its off.
I'm using less gas than you at the moment -and I'm heating water AND cooking on a gas hob!!!

Yikes! No gas hobs/cookers, etc. here! I've no idea what a "frost stat" is, but I'm fairly certain that the boiler isn't firing up at all. I'm at home all day and I'd hear it if it was.

macman wrote: »

A frost 'stat will raise the temp of the CH flow pipe, not the hot water cylinder?
OP, turn the boiler off and power it down from the mains switch. If the hot water is still heating back up after you run some off, then clearly you have a back-up system (immersion heater) that is permanently on-that is what running up your kWh's, not the boiler electronics or pilot light in standby.
You'd surely know anyway if your boiler was firing to heat the hot tank when it's supposedly 'off'?

There's definitely no "back up" system (except the electric immersion heater, which is off all the time and wouldn't affect my gas consumption anyway). The boiler never fires up either. I'm at home all day, so I never use the timers (and I have double-checked that they are all off). I turn the boiler on manually... And it never ever fires up unless I flick the switch.

The only gas powered device in the house is the boiler, so there could be no other system running up our gas consumption.

The two "strange" things are that the gas usage is so high, and that I have plenty of hot water! I can only imagine that the two are linked. But when the boiler is never on... that seems very odd to me!

retiredin2011 wrote: »

My gas water heater pilot light uses 1095 kWh of gas a year and the separate warm air heating pilot light uses 5 kWh a day, currently switched off.

I am waiting for the day when my 24 year old warm air heating unit is no more economically viable to repair then I shall install radiators, :rotfl::rotfl: unless modern gas boilers use pilot lights.:eek:

And before someone says replace the warm air with a new unit I would do that if it wasn't for the fact that a new warm air unit cannot be placed where the old one is, according to SG:cool:

Ahh... the pains of warm air systems, eh? I think all the neighbours have installed radiators, but I really like the warm air!

Anyway... From what you're all saying, I'm using a crazy amount of power.

I'm tempted to turn the boiler off... but I don't really know how to do that (or how to re-start it and re-light the pilot lights again). I don't want to gas myself or blow up the house!

I'll have to look for an instruction manual online and see if I can figure out what to do (and how to adjust the pilot flames if necessary).

penrhyn wrote: »

They haven't used pilot lights for at least 15 years.

Well, there's definitely two of them in my ~10yr old boiler. I just took off the front panel to check.

Cardew wrote: »

My understanding from the OP's post is that the 4,745kWh per year is referring to Gas kWh consumed by the pilot light - not electricity kWh.

Yup, that's right. I was only looking at gas consumption.

Cardew wrote: »

This thread was published 7 years ago:

https://forums.moneysavingexpert.com/discussion/comment/6378117#Comment_6378117

You will see in post #13 that my pilot light was using 9.5kWh a day - about 3,500kWh a year.

Oh -- that's interesting. So maybe my gas usage isn't that crazy and a tweak of the pilot flames would reduce consumption to a normal level.

I wonder (in this weather) whether it would be cheaper to turn off the gas boiler and just use the electric immersion heater for hot water...?

Robin9 wrote: »

OP Are you saying that your GAS meter advanced by 50 units over a 9 period - you don't give a period but 4475/550 - and 1 dialled unit is approx 11kwh ?

Or is the 550kwh your ELECTRIC reading ?

Erm... 50 units? A 9 period? A dialled unit?! Sorry -- not sure what your mean! The measurement I gave was 550W of power (not 550kWh of energy), which is why there was no time period. (A Watt [of power] is a Joule [of energy] per second.)

I took a number of measurements (one a day for a week) which shows that the gas consumption is at a fairly constant level. The calculation I used (in case anyone wants to check my maths) was as follows:

First reading: 7:55pm 13/7/2014 -- 21,694.532 m^3
Last reading: 10:20pm 20/7/2014 -- 21,702.683 m^3

Time period: 7 days, 2hrs and 25mins = 170.416667hrs
Consumption: 8.151 m^3 = 93kWh
(Conversion from m^3 to kWh provided by: http://energylinx.co.uk/gas_meter_conversion.html)

93kWh over 170.416667hrs = 546W.

Thanks again for everyone's comments! I guess the next step is to figure out how to turn off the boiler to confirm that it's that running up the usage and heating the water, then trying to turn down the pilot lights if that's possible... Hmmm...

macman

If the boiler isn't firing up then the only thing that can be heating the hot water is the immersion heater. The switch may have failed although you say it's off.

brewerdave

Have to agree with macman. Surely the motorised valve to feed hot water from the boiler to the secondary coil in the hot water tank ,wouldn't operate when the boiler is "off"?

Cardew

brewerdave wrote: »

Have to agree with macman. Surely the motorised valve to feed hot water from the boiler to the secondary coil in the hot water tank ,wouldn't operate when the boiler is "off"?

Gravity could enable hot water tank to get hot water from the gas CH boiler. The motorised valve will not close this flow.


In the days of open coal fires with a back boiler(I had one) gravity was the normal method of providing the majority of domestic hot water.


http://en.wikipedia.org/wiki/Back_boiler

Water circuit

The back boiler is typically used with a gravity feed circuit to the hot water cylinder,


Back boilers require that the hot water or central heating system be able to disperse all of the heat captured from the fire, otherwise boiling or overheating of the water can occur.

Bear in mind that the OP's pilot lights are using over 12kWh per day. Given the very little water capacity in the boiler jacket, the hot water will simply circulate.

macman

But surely the CH is off anyway at this time of year, so a faulty 3 port valve can't be allowing CH circuit water to enter the hot tank? Whatever the vagaries of this particular boiler install, if it's not firing, then it can't be heating water...

Cardew

macman wrote: »

But surely the CH is off anyway at this time of year, so a faulty 3 port valve can't be allowing CH circuit water to enter the hot tank? Whatever the vagaries of this particular boiler install, if it's not firing, then it can't be heating water...

Yes the CH is off! and yes the boiler can supply warm water to the HW tank even if not firing.

Why do you feel the 3 port valve is Faulty? It is working exactly as designed.

The 3 port positions are:

A. To CH circuit(i.e radiators/UFH)

B. to HW tank

C. To both CH and HW tank.

There is no 'off' position where no water can pass through the valve.

The valve cannot under any circumstances shut off water to either the HW tank or CH circuit(or both). If it could you would have a potential explosion on your hands.

Description
A motor drives the valve to one end of travel (central heating, port A). If power is removed the motor turns off and a spring returns the valve to the other end of travel (hot water, port . For both hot water and heating (mid position) the motor is stalled by feeding it DC through the diode and resistor. A pair of micro switches and a cam in the valve control the switching of the diode in the mid position and the sequencing of the boiler. The motor is a synchronous one so feeding it (pulsating) direct current through the diode locks it to zero frequency (stationary) with sufficient detent force to remain in the mid position against the spring force.

With the power off to the central heating/hot water the 'default' position is that 3 port valve will allow water from the boiler/back boiler(or log burner if so connected) to enter the hot water tank.

Using 12kWh+ a day from the pilot lights on the OP's boiler will cause the water in the boiler jacket to warm up and gravity will feed it to the HW tank.

The principle is the same as a back boiler on a coal fire heating water that will be fed by gravity to the Hot Water tank.

I am sure many off us who have had a back boiler(with a blazing fire) have experienced the situation(with the CH off) where the water in the HW tank actually boils and we need to run off some hot water into a bath.

I really cannot see the problem in understanding the OP's situation. His 'flamethrower' pilot lights in the boiler are heating water and gravity is taking it to the HW tank via a correctly operating 3 port valve.

r2015

I guess the next step is to figure out how to turn off the boiler to confirm that it's that running up the usage and heating the water

Turn the gas off at the meter.

esuhl

Hey, Cardew -- that's pretty much what I think is happening.

The previous boiler only heated air, and we used an electric immersion heater for water. When the current boiler was fitted, some kind of "gravity feed" water circulation system was set up, where water from the hot water tank loops down through the boiler and back into the tank.

I really had no idea it was possible for pilot lights to consume so much gas! 550W just going to waste! I don't usually use that much electricity!

When I get a moment I'll see if I can find an instruction manual for the boiler so I can figure out how to turn the pilot lights down... and how to turn it off completely.

Even if I turn the pilot lights down, do you think it would be more economical to shut off the gas during summer and use the immersion heater instead?

esuhl

macman wrote: »

If the boiler isn't firing up then the only thing that can be heating the hot water is the immersion heater. The switch may have failed although you say it's off.

I just checked the switch. When I flick it on, I can hear the same "fizzing" sound from the tank as I always have when I switch on the immersion heater.

The hot water pilot light in the boiler went out a while back (and couldn't be re-lit). In Spring a part was replaced (the "pilot light assembly"?). As far as I can tell the "flamethrower pilot light" must have been set up by the engineer back then.

I think this is starting to make sense! Thanks again for all the ideas, everyone!