Question regarding LPG quantity and usage...

[tooplanx]

I'm just using the 88% figure, it won't change the calculations to any big degree anyway.
On that basis then you might say that those bottles are ony being filled to 57.4%, 1509/2627, or if you only used 3.25 bottles in december, 74.2%, 1509/2035, which is what you suspect (75%), get that weighing scales out of the bathroom.

That's interesting. I think I'm satisfied now that the recorded kwh usage in the boiler (as a daily average) is what I should expect.
So now the discrepancy seems to be with the kwh usage when compared to what the bottles should be containing. I will be weighing the new bottles which should arrive tomorrow.

According to the my calculations, if I'm paying £75 per bottle and it should contain 656kwh of gas, then that should work out at 11.43p per kwh.

I need to monitor over the next few weeks.

 

[fixitflav]

I will be weighing the new bottles which should arrive tomorrow.

If the supplier is giving you short measure, that sounds serious! Somebody should be told.

 

[tooplanx]

If the supplier is giving you short measure, that sounds serious! Somebody should be told.

Yes, it certainly does! But I better make sure I've checked everything properly before I start making accusations.

 

[Johntheo5]

How do you get all the contents out?, do you just run on one bottle at the time and let it run out and change to another?

 

[Harry Bloomfield]

Yes, it certainly does! But I better make sure I've checked everything properly before I start making accusations.

For the steel gas bottles, to check the contents remaining, I use a pair of bathroom digital scales, known to be perfectly accurate. I convert the pounds and ounces stamped on the bottle, to kg, then chalk it on the side of the bottle for future reference, then I can work entirely in Kg.

 

[Mottie]

Isn’t there some kind of calorific multiplier when working out gas usage? Dunno how you’d find the calorific value of Propane.

 

[Johntheo5]

It's ~ 656/47, 13.96kwh/kg.

 

[fixitflav]

It's ~ 656/47, 13.96kwh/kg.

Gross

 

[tooplanx]

How do you get all the contents out?, do you just run on one bottle at the time and let it run out and change to another?

It's a four bottle system. Two in use at once and two ready to switch to when the first two run out. It's on an auto switcher.

 

[Johntheo5]

Might be no harm to weigh the two you remove and check against their tare weight in case this auto switcher is switching early for some reason or other.

 

[snb1]

It's a four bottle system. Two in use at once and two ready to switch to when the first two run out. It's on an auto switcher.

never rely on the auto switch over valve as it will switch over when you still have upto 5% left. even more if the temp is cold. leave the bottles turned off on 2 until you run out and then switch them on.

 

[tooplanx]

never rely on the auto switch over valve as it will switch over when you still have upto 5% left. even more if the temp is cold. leave the bottles turned off on 2 until you run out and then switch them on.

Good shout. I was wondering if the switch over valve was properly efficient. It won't cause damage to the boiler if it's repeatedly running out of gas (I know it won't be often, but over 10+ years it could have an effect)?

 

[Mike13]

If the supplier is giving you short measure, that sounds serious! Somebody should be told.

Trading standards would take an immediate interest.

 

[tooplanx]

Well, I tried weighing the new bottles, but failed. They're meant to have a gross weight of 105kg, so I wasn't able to lift one clean off the ground to be able to then push a weighing scale underneath. Or at keast I wasn't able given the space they were in. I tried rolling on its edge to get it on the scales, but the pipe (already attached) was restricting the movement I had. I was also concerned it might crack my scales as they are glass topped, so I had put a rubber mat on top, which would obviously affect the overall weight too.
I tried removing the pipe but it was so tight I couldn't do it with my spanner.

I did kind of get it on the scale but it was clearly such a kess than ideal way to weigh it that the results would've been worthless, so I gave up!

Anyway, had some cold weather yesterday which showed the condensation line on the new bottles and it was much higher than I had estimated in the previous bottles, so maybe nothing to worry about. However, I will keep monitoring it!

I think my house is just very poorly insulated!

 

[kidgreen61]

Gross weight 105kg???
That would suggest the tare (empty weight) of the bottle is 58kgs. 20 something would be nearer the mark.