Gas heater usage not adding up

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boflit

82 posts

Master Geek

#198243 1-Jul-2016 17:02

We have a masport heater in the living room, this is our first winter in our house so still getting used to it. A quick squizz on the net says a heater at low should get a 45kg bottle around 368 hours, though I am sure that is an over estimation or only applies to brand new efficient stuff.

Anyway, that figure is for 1 bottle, we have 2 and have used up both in 2 months, yet we only use it in the evenings and perhaps the afternoon and evening on the weekends. I estimate we have it on for about 172 hours a month, so at low we should be close to 2 months per bottle, yet we have somehow used 2 bottles in 2 months and when I called Elgas they said we did well getting 2 months, I said that contradicts their own website, but still, apparently they reckon they have customers that go through a bottle a week. I find that hard to believe, unless they have it on full all day every day.

Just wondering what other users experience is of indoor heaters and 45kg bottles. I would be worried we have a leak, but the system was been serviced before we started using it. So I'm coming to the conclusion our heater is grossly inefficient or the bottles we had delivered weren't full.

Any input appreciated.

andrewNZ

2487 posts

Uber Geek
Inactive user

#1584238 1-Jul-2016 17:12

Depending on where you live, it is common for bottles to run out before they are empty. This is because propane and butane boil at different temps. At low temperatures the butane stays liquid and is unusable.
Many companies weigh returned bottles and refund unused gas.

Also, to know how much gas the heater will use, you need to actually look at its manual. Generic info is useless.

boflit

82 posts

Master Geek

#1584245 1-Jul-2016 17:19

good point, I should get the manual and check, or atleast the model number. But we are in Auckland, so its not too cold. Its mainly been on to take the edge of is all, hence why only on low, and in fact gets turned off early some evenings as it gets quite warm.

My estimate of 40 hours a week would be at the top end of our usage, so unless it is grossly inefficient, something else is wrong.

richms

28218 posts

Uber Geek

Trusted

Lifetime subscriber

#1584290 1-Jul-2016 18:01

Auckland still gets cold enough that butane will not evaporate in the cylinder, if they get no sun and are on the cold side of the house etc.

As you take gas out, they cool, so then it will sit with the butane not doing anything and the regulator will switch over to the second cylinder when the first still has some in it, so you can switch it back once the temperature stabalises and get a bit more from them.

Richard rich.ms

Aredwood

3885 posts

Uber Geek

#1584321 1-Jul-2016 18:55

Have a look at the rating plate on the heater. It should state it's gas input rate. Will write a bigger answer when not using my phone

boflit

82 posts

Master Geek

#1585174 3-Jul-2016 17:36

Aredwood: Have a look at the rating plate on the heater. It should state it's gas input rate. Will write a bigger answer when not using my phone

apparently it is 29mj. Though I assume that is at maximum, we only ever run it on low.

I see an example of 15mj at 4 hours a day should last 37 days, so that is probably on a par with what we got I guess, 2 bottles, lasted about 2 months. Just seemed high initially, and the engineer who serviced it reckoned about 3 months, I assume he didn't take note of the consumption.

I think I will be telling my daughter to be a bit more frugal with her usage after school, I can't be justifying $200 every 2 months for gas.

Aredwood

3885 posts

Uber Geek

#1585245 3-Jul-2016 19:31

Each 45kg bottle contains 2250 MJ. The rating plate might quote a gas consumption on low. But most importantly, you need to find out how efficient it is. As it could be an inefficient gas fire. In which case a plug in electric heater would be cheaper to run. But it could also be an unflued heater, meaning it would be 100% efficient. But with the downside of lots of extra moisture in the house. Does the rating plate state a output figure? If so you can then calculate the efficiency.

And is the gas heater the only thing that uses LPG? Or do you have Gas cooking and hot water as well? As the best option might be to switch your power to Flick electric, Use a plug in electric heater when spot prices are low. And use the gas heater when prices are higher. And do you rent or own the house?