# Baxi multiheat 1.5 - known problems wood pellet problems?



## MAJJ (5 Feb 2009)

Hi Folks,

Really need some help on behalf of my folks, they have a new build 1.5 years in it, built with energy efficiency in mind from the off which was built into the fabric of the house, concrete with internal/external insulation, air tightness test, heat recovery vents, solar panels, underfloor heating and a very hungry boiler.

I'm getting all my information from my father who it has to said may have some details wrong but he is worried hugely about the cost and usage of pellets. They currently use bags and are in the process of switching to bulk.

This is based on a house of 1800 square feet, with two older adults using average amounts of hot water and most of the zones turned to the minimum.  The main thermostat is set to 15 degrees and the other zones have controls to change plus or minus 4 degrees of the main thermostat temp.   

I ascertained that the house is looking to maintain 15 degrees 24/7 with an increase of about 2 degrees in the evening in the main living area.

I have been told that the usage in about 3.5 weeks is approx 100 bags or 1 tonne. Since they bought the boiler it seems to be consuming more fuel, it is cleaned regularly both ashes and rods. 

They have been told unofficially that the boiler they have is based on an old inefficient design and the model is being replaced with new boilers in new install.

Based on the above 'facts' - does this sound like a problem? For the size of the house is the usage too much, he is convinced he is using twice what he should be.

Thanks for taking the time to read. I'm no expert and need your help.
majj


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## poppy1 (6 Feb 2009)

Hey

Don't know if this helps but we have a windhager wp boiler and we use 3 tonnes a year. The heating is set at 20 degrees and is on from 4pm to 10 pm (longer at w/ends) and it also fills a 300litre water tank. 

We have regualar rads and solo ones and the house is 2200sq ft.

So i defo think he should get it looked at or speak to someone.

We buy in bulk and have purpose built storage.

Best of luck


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## MAJJ (6 Feb 2009)

Hi Poppy1, thanks for taking the time to respond with your advice.


Any one else have some advice or know about issues with this boiler?


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## fmc (6 Feb 2009)

HI Majj def sounds like something is up get a heating engineer out or go back to where they bought it. there was a lot of dumping of old designs in pellets and gas boilers here from other countries as they moved to higher efficient units and unfortuantly thats why renewables is taking a rap at present.


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## MAJJ (6 Feb 2009)

Thanks fmc, thanks for that, I suspected that too.

He has taken it up with the supplier so I wanted to jbe forewarned with knowledge to help him when they start their bull.....  default response.

I am hoping to find someone with the same boiler and issues.


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## jabh (7 Feb 2009)

The consumption seems high to me too. I have a Pellx pellet burner installed in a Buderus G115 oil boiler the burner is very efficient but the boiler isn't designed to deal with the ash so the efficiency gets less and less between cleanings. My house is about 2500 Sg ft not very tight and with single digit nightly temps F this past week and highs below 25 in the last five days I’ve burned 700 lbs of pellets. 140 lbs a day. I’d check the combustion gases with a meter to determine a combustion efficiency, 90 % range should be achievable and look at the stack temperatures. Also, too much draft can suck the heat out of the most efficient boiler. Hope this helps.


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## MAJJ (7 Feb 2009)

Hi jabh, that adds more fuel to the fire!!   The consensus seems to be that there so is something well wrong with the boiler.   

Thank you,

majj


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## ninsaga (7 Feb 2009)

poppy1 said:


> Hey
> 
> Don't know if this helps but we have a windhager wp boiler and we use 3 tonnes a year. The heating is set at 20 degrees and is on from 4pm to 10 pm (longer at w/ends) and it also fills a 300litre water tank.
> 
> ...



Poppy1 - when you say set to 20degrees - is that the rad temp you refer to? What is the boiler temp set to & the tank boiler set at? How is that determined?

ninsaga


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## jabh (8 Feb 2009)

20 degrees F was the max outside temp for the 5 days of the 700 lb consumption.  My boiler is set at 165 F and I don't have a boiler tank, unfortunately.  My boiler being designed for a fast cycling oil gun is too small for the pellet burner application.  My point is that even with all my inefficiencies and larger house my consumption is similar to the more purpose built system in a smaller tighter house


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