High gas usage for boiler.

[stevedurban]

Ok then, the flow pipe from the boiler should be absolutely scalding and you should only be able to touch it for a very short time.

Yes - scalding hot

Not sure if it’s right - but both sides of the ABV are also scalding.

(Hot pipes in red!)

 

[John.g]

They certainly shouldn,t especially when the index is set to 0.5? (5M), there may be a bit of crap under the seat, with the boiler running slowly, adjust (anti clockwise) the setting knob, you should hear some noise if the ABV starts opening at ~ 0.3/0.4, then reset it back to 0.5.
If it is in fact passing badly, the boiler return should also be very hot.

 

[stevedurban]

They certainly shouldn,t especially when the index is set to 0.5? (5M), there may be a bit of crap under the seat, with the boiler running slowly, adjust (anti clockwise) the setting knob, you should hear some noise if the ABV starts opening at ~ 0.3/0.4, then reset it back to 0.5.
If it is in fact passing badly, the boiler return should also be very hot.

They certainly shouldn,t especially when the index is set to 0.5? (5M), there may be a bit of crap under the seat, with the boiler running slowly, adjust (anti clockwise) the setting knob, you should hear some noise if the ABV starts opening at ~ 0.3/0.4, then reset it back to 0.5.
If it is in fact passing badly, the boiler return should also be very hot.

So I just tested as described. The tank was calling for heat. I adjusted the abv to around 0.3 and no different sounds. When the tank stopped calling - I could hear a new sound which was obviously water going through the abv - I’ve never heard this noise before.

I thought the idea of the abv was that when the boiler ran and then stopped calling for heat - and the valves closed - the water should pass through the abv to allow the pump to slow without excess pressure on the pump? If the abv was doing it’s job (and there isn’t another one in the boiler) then I should have been hearing that sound every time both valves just closed?

 

[stevedurban]

Can you see the actual boiler temperature from the boiler display to confirm that the high setting 0f 6+ is actually reflected in the boiler temperature.
Also, as suggested above, turn the cylinder stat up if the motorized valve is shut and ensure it opens and turn it down if the motorized valve is open and ensure it shuts.
If the boiler temperature is as high as it might be, 75C+, and if the DHW temperature doesn't feel scalding then a fair indication that its temperature is being controlled to its setpoint of 50C. (should really be 60C, for legionella protection).

Just to confirm - I set the tank stat to 60 - and after a while tested the water temp of the nearest tap - and it was 59.9

 

[John.g]

It was probably never set up properly, you are possibly the first person to touch it, if the no flow pump head is less than 5M (0.5bar) then the ABV will never open, so you can adjust it around that setting (of 0.3) so that it only opens when both mot.valves shut and the pump is on overrun.

Just to confirm - I set the tank stat to 60 - and after a while tested the water temp of the nearest tap - and it was 59.9

Well, back to square one so re high gas consumption as the cyl temp is being controlled and even if left enabled all day shouldn't account for that excess gas usage which was mad during the summer , see post #31, even 12kw current usage seems quite high once house up to temp?.
You said you might try running on the immersion for a day or two to rule out HW usage?.
Can you also not programme the HW cylinder to be heated for a few hours in the morning?, can't remember if you said that it has its own programmed zone.

If the ABV is passing then that will consume a fair few M3 of gas via unlagged copper pipes, the easiest way to check it is when/if the system is cold in the morning and just after the boiler fires up, keep your hand on the vertical ABC (downstream) pipe which should remain cold for a long period, if not leaking it could still possibly feel very hot due to conduction.

 

[ShaunCorbs]

Abv is shot by the sounds of it as it shouldn’t be passing when the system is on / running

 

[stevedurban]

It was probably never set up properly, you are possibly the first person to touch it, if the no flow pump head is less than 5M (0.5bar) then the ABV will never open, so you can adjust it around that setting (of 0.3) so that it only opens when both mot.valves shut and the pump is on overrun.


Well, back to square one so re high gas consumption as the cyl temp is being controlled and even if left enabled all day shouldn't account for that excess gas usage which was mad during the summer , see post #31, even 12kw current usage seems quite high once house up to temp?.
You said you might try running on the immersion for a day or two to rule out HW usage?.
Can you also not programme the HW cylinder to be heated for a few hours in the morning?, can't remember if you said that it has its own programmed zone.

If the ABV is passing then that will consume a fair few M3 of gas via unlagged copper pipes, the easiest way to check it is when/if the system is cold in the morning and just after the boiler fires up, keep your hand on the vertical ABC (downstream) pipe which should remain cold for a long period, if not leaking it could still possibly feel very hot due to conduction.

So for the past 3 days I’ve set tado to only turn the heating on for 2 hours a day (11-1) - and the usage hasn’t changed. I also checked when it was off that turning the tank stat up didn’t call for heat and open the dhw valve - and it didn’t - so we know that’s off.

Today upto 6pm so far I’ve used 148kwh!! It’s crazy!!! There has to be something wrong somewhere!! Just not sure where to turn!!

On the abv pipes - it’s only a short way to the return pipe coming out the tank - so that pipe always seems to be hot (rightly or wrongly?)

If the HW is off - should any heat be coming out that pipe from the tank? Or is the fact it’s hot either a fault or the ABV working?

 

[John.g]

So you have used 148kwh in, 3X2, 6 hours in total which is almost 25kwh (per hour), is that correct? Is it a 24kw boiler, can't remember?.
Can you set up a camera to monitor the Gas Meter to monitor those 2 hours each day or have you noted the readings at the end of each day period and start of next days period to ensure no usage in the intervening time?.

If the ABV pipework has been installed then the supply to it should be teed off before any motorized valve, can't see it properly but if its taken off before the (or any) HW M.valve then correctly installed, so as long as the boiler is firing the ABV is "live" and can leak, but boiler will hardly be firing (we hope) with both M.valves shut?.

Just thinking, the boiler is/should only be started when either of the M.valves open by means of (end) switches in their actuators.

 

[stevedurban]

So you have used 148kwh in, 3X2, 6 hours in total which is almost 25kwh (per hour), is that correct? Is it a 24kw boiler, can't remember?.
Can you set up a camera to monitor the Gas Meter to monitor those 2 hours each day or have you noted the readings at the end of each day period and start of next days period to ensure no usage in the intervening time?.

If the ABV pipework has been installed then the supply to it should be teed off before any motorized valve, can't see it properly but if its taken off before the (or any) HW M.valve then correctly installed, so as long as the boiler is firing the ABV is "live" and can leak, but boiler will hardly be firing (we hope) with both M.valves shut?.

No sure what you mean about 3x2? Heating comes on at 6am - and goes off at 9pm. Water is heated only 11-2

I will be able to see half hourly reports from octopus energy tomorrow as the smart meter uploads each night.

I can see yesterdays report already. It seems to be about .7m3/hour From 6.30am-12pm. It doesn’t seem to peak between 11-2 (the water was on that setting already yesterday!)

As for the ABV - It’s piped before the valves - so that seems right! It seems to overrun for about 5 mins when the valves shut.

 

[ShaunCorbs]

Turn heating and hot water heating off and see what your software registers

Boiler shouldn’t fire at all when everything is set to off