The new heating system / a work in progress.

[noelsquibb]

ooeerrr going a bit off topic arent we ?
Good to learn that time at uni didnt stop you adding to the 'good hospital guide'
And theres nothing wrong with MTB ( apart from the uphill bits ) Ive occasionally towed downhillers back up, with their hand on my shoulder. They reckon its more exciting than going down.

Yup Jamie Squibb, now on Yamaha cos Kawasaki no longer making 2strokes

[pottsiwebber]

ooeerrr going a bit off topic arent we ?
Good to learn that time at uni didnt stop you adding to the 'good hospital guide'
And theres nothing wrong with MTB ( apart from the uphill bits ) Ive occasionally towed downhillers back up, with their hand on my shoulder. They reckon its more exciting than going down.

Yup Jamie Squibb, now on Yamaha cos Kawasaki no longer making 2strokes

I thought it must be Jamie, you must be proud / terrified on a daily basis. Respect to your lad it takes guts and an enormous amount of skill to do what he does. People dont realise exactly how much skill is involved they seem to think if you point a bike at a jump and go fast enough you will land safely on the other side... yeah right!

Last time I hopped on a crosser I did 3 laps of track on my cousins CR250 fell of on the same hip jump 3 times (too many jumps and corners to remember) and was knackered. Note to self: Never buy son a MX bike nasty dangerous things.  Hmmm somehow I doubt I'll manage to stick to that one...

[noelsquibb]

People don't realise exactly how much skill is involved they seem to think if you point a bike at a jump and go fast enough you will land safely on the other side... yeah right!

Anyone who has tried to tame a MX bike knows but everyone else thinks it looks easy.
He was getting air before he could walk.
Learnt to lob the contents of the cot over the raised side then lob himself onto his prepared landing.
Jumping off picnic table aged 2 wearing just a pair of wellies
On my bike while still in nappies, sat on the fuel tank with a cross bar welded to the downtube for his feet.
All riding is developmental and progresses incrementally
Spends a lot of time visualising himself doing the move and will only try something a bit different when he has the visualising bit nailed.

'Look where you want to be'    deep stuff and incredibly effective.

I try to avoid pride and accept the risks as parents of soldiers off to Helmand do.

If you do get your lad on a bike it means you will need something to be able to keep a close eye on him as he learns
to ride 

[pottsiwebber]

O.K. a bit of a (very) quick update, I just thought I'd post a few notes on how the system is operating.

After living with the pellet boiler for 6 months or so I can say I'm pleased with it and my thoughts on the boiler are as follows:

1) The feed mechanism could be better in terms of cleaning requirements. I guess it’s a trade of between a compact design, cost and maybe efficiency. I'm guessing because I'm not well versed in the different feed and burner operations in pellet boilers. The bottom feed via the auger results in a build up in the 90 degree elbow under the burner which if not regularly removed (by chipping it away) causes the shear bolt on the auger feed to... errr shear. This is not a problem once you are used to the boiler operation but it's caught me out a few times when I've thought "that will go another day before I have to clean it" then I wake up to a cold house and no hot water.

2) The lack of a timer input for the DHW is a big oversight as far as I'm concerned. I quickly overcame this (as described somewhere above) using a plug in timer a 230vac relay and a 10kOhm pot but I shouldn’t really have had to resort to that.
I've been keeping a spreadsheet record of pellet usage and since the heating went off I have confirmed that with the timer circuit charging the thermal store for 4 hours in the afternoon / evening I use half as many pellets as with the timer switched off!

3) There is no option for switching the boiler on and off completely using a timer. I understand that the boiler is supposed to maintain a set temperature to avoid condensation but in the summer? This again is in my opinion an oversight as I've manually switched the boiler off all day and switched it back on before the DHW calls and the boiler temperature is still high enough not too see any condensation. The boiler is fitted with an outdoor temperature sensor as well as an internal sensor so I'm sure a bit more intelligence in the control could have been used to shut the boiler down completely in warm weather.

So a few niggles but on the whole for the price and the automation I still haven’t seen anything that comes close, you just need to be aware that a pellet boiler is not like an oil or gas boiler and I doubt they ever will be despite manufacturer’s claims. They are solid fuel appliances so you need to expect to get your hands dirty and in the case of my boiler to be capable of changing a shear bolt, which I fear still excludes a very large percentage of the population. Then again I like to think of us as energy pioneers, it’s going to take decades for the rest of the population to catch up and by then the technology will have improved.

The solar is on hold at present but I hope to install the controller and ancillaries over the next few months to spread the cost of the installation and I'll post some more photos as and when.

[Brandon]

out of interest, what are you paying a ton at th moment?

[Fintray]

Pottsiwebber, I had the same problem with a coal fired boiler many years ago, it used "coalflow pearls" and I eventually had had enough of taking the burner out to clean the 90 degree bend that I fitted the boiler with a "reclaimed" oil burner  that was during the days of cheap heating oil!

[pottsiwebber]

out of interest, what are you paying a ton at th moment?

£233 delivered and stacked in 10kG bags. I only have 2 suppliers in my area, the first guy I tried was closer but was more expensive. He matched the lower price but can only deliver pallets and uses a delivery company who let me down on the first load when I wanted to commission the boiler!

The guy I use now got the pellets to me in time to commission and off loads the bags into my store so. Needless to say the first guy wont get any of my business in the future.

[pottsiwebber]

I've been experimenting switching the boiler off after its charged the thermal store then switching it back on the next day to recharge. During this time I've saved a lot of pellets but got through a lot of shear bolts which was / is odd but I think I know why.

Previously I've just been switching the boiler off and letting the pellets smoulder down the feeder until they go out. Ever time I restarted the boiler I would end up with sawdust at the end of the auger which compacts and eventually shears the bolt.

Yesterday I stated the boiler after previously stopping it the day before but this time I didn't let the pellets smoulder down, instead I cleared the burning pellets off the top and made sure I only had unburnt pellets in the burner. When I restarted there was no sawdust.

I think the unburnt pellets in the feeder are being dried it as the pellets smoulder away and when I restart they break down in the auger and block it.

Sound plausible to any pellet experts out there?

I'll try some more techniques and report back.

[pottsiwebber]

After speaking to Terrier who installed the boiler it appears I may be the victim of horse bedding pellets. 

The last lot of pellets delivered were in unbranded bags and not the usual excellent quality Balcas Brites pellet bags. The supplier assures me they are the same pellets but in different bags but unfortunately I don't believe him. He didn't sound surprised enough when I informed him of my problems but I have his assurance that they will be Balcas branded bags from now on. My suspicion is that he ran out of Balcas pellets and as he also happens to supply horse bedding pellets delivered a load of those instead but its hard to prove so I'm left cleaning out the boiler more often until I use them up. He must have made a tidy profit selling them to his customers if they were horse bedding pellets but hopefully hes had enough complaints not to do it again!

[pottsiwebber]

Winter looms on goes the heating... wait a second why does my auger keep getting blocked.
 
Bloody Lambda sensor has gone kaput again! Thats the second one in 12 months!
 
In case anyone is reading this who has or is thinking of buying a bottom feed auger driven pellet boiler I will outline what happens when your Lambda sensor goes kaput.
 
So thee boiler starts up and starts to check o2 but its very low (coz the sensor is farked) the fan speeds up... no still low o2, so the fan speeds up... no still low o2, so the fan speeds up until eventually there is a small hurricane blowing through the burner. The pellets will burn back into the auger and cause ash etc. to build up around the bend under the burner, the boiler keeps running like this for bit until it shuts down normally.
 
Whilst idle the pellets in the bend partially bun and smolder away happily until the the boiler starts up again at which point the auger will start and initially feed pellets and everything will look OK. However, due to the ash etc. getting stuck at the bottom of the bend the bend will become restricted and the auger will slowly start to crush some of the pellets into sawdust until a large solid lump of sawdust builds up and shears the shear bolt on the end of the auger. I speak from experience as a man with a bag full of shear bolts, I'm like a formula 1 pit crew changing those things now!
 
You can also take a look at the o2 readings whilst its running (if your boiler allows you to) and it will probably look like mine bouncing around all over the place on start up before plummeting to some ridiculously low figure causing the above scenario to occur.
 
I currently have a disconnected Lambda sensor and all power levels set to try and achieve an o2 of 129 which is the default value when you disconnect the probe. So much for Lambda probe efficiency.

[djh]

Bloody Lambda sensor has gone kaput again! Thats the second one in 12 months!

I don't know much about them but I think lambda sensors can suffer from "poisoning" and pages like this one - http://www.picoauto.com/applications/lambda-sensor.html - mention carbon and silicone as possible contaminants. Did those dodgy pellets have any different ingredients in them?

[pottsiwebber]

Oh god damn it!!  The Lambda sensor appears not to be faulty. Recieved a new one from Malcolm (Terrier) at MGL and the o2 is still shooting up and down, it looks as if the Lambda "control" unit is faulty. I've had alook and all there is inside is a 230vac - 12vac transformer for the Lambda heater and a helpfully sanded down IC plus couple of caps and transistors. I'm thinking A-D convertor? Digital output to main controller? Anyhoo Maclolm is sending me his unit to see if it is faulty. It seems the RHI and MCS accrediatation has forced him down the route of abandoning the Kostrzewa in favour of a more expensive MCS approved boiler which he will be selling from now on so he has his old boiler in storage.

Oh and now my DHW coil is airlocked and no matter what I try it wont fill. I'm gonna get medieval on its ass!!!

[pottsiwebber]

Tis the season... for everything to go tits up!

I overcame my airlocked DHW cylinder coil feed by cutting in a T after the pump, fitting an isolation valve and a hose tail then filled it with a hose. The Lambda controller turned out to be working fine with the new Lambda Sensor after leaving it on for a day. I then stated experimenting with fan and feed settings with the Lambda disconnected to try and get a nice combustion at all power settings. I've been reading various posts on a Polish forum (badly translated by Google) and have come to the conclusion that a Lambda sensor is pointless if you are burning a fuel source with known combustion rates i.e. pellets. It seems the Poles burn a lot of coal and grain and use the Lambda to adjust the air flow rate automatically to compensate for different combustion rates.

Anyway, I got the boiler running really nicely with no lambda sensor with the best combustion I've seen to date... then it all went to rat s**t.

I suddenly found loads of sawdust every day or so in the feed elbow which is left blocks the feeder and shears the bolt. Marvelous! After more badly translated forum browsing I have discovered that upon inspection my feed screw is worn so badly it is grinding the pellets to sawdust. These are under warranty for 2 years so I've got one in the post on its way to me and I think the problem has been that the boiler has been burning with too much air and consequently burning too low in the feed elbow heating the end of the screw weakening the steel leading to the wear.

The poor combustion over the past year (including not enough air at times) has also caused a considerable build up of... errr Oh, how I wish it was better in the boiler and flue resulting in... a bloody chimney fire!!! 

I was in rush as usual and wanted to remove the feed screw to measure it in case I needed to order a new one as there are two lengths available. I switched off the boiler, turned on the exhaust fan for cleaning then flicked the burning pellets out of the burner at which point some of them must have been sucked through the boiler by the fan and ignited the waste products at the back of the boiler and in the flue.

I've learnt a couple of valuable lessons here 1) Always let your boiler cool properly before cleaning it. 2) Clean your boiler and flue regularly 3) make sure you have hose pipe long enough to reach your flue.

Thankfully I had 3) and put the fire out not before running around like a headless chicken thinking "what do I do, what do I do!"

The only damage done was the exhaust gas temperature sensor getting fried which means I cant run the boiler! Arrrghh!!   

Again Malcolm came through, answering his phone on Sunday and putting a sensor in the post along with the screw feed which was posted today.

I've cleaned everything out dismantling the flue at the back of the boiler just in case but there was only a bit of crusty ash. Now I just have to contend with the Christmas post waiting for the bits to arrive... oh and a less than impressed wife who is ready to have an oil boiler installed! Hopefully I'll get everything working properly and that along with the usual oil price hikes in the news will calm her down.

On the plus side the WBS is doing an amazing job of keeping us warm and heating the DHW with only a really small amount of help from a convection heater and the immersion heater only if we use an exceptional amount of hot water. Its incredible how much heat a little 4kW WBS with back boiler can produce if you run it all day long!

I'll post again with an update, hopefully with good news! 

[pottsiwebber]

Still waiting for postie to deliver my sensor or my feed screw but I'm warm again! After a thorough cleaning and inspection I tried a few resistor combinations to try and fool the boiler into thinking the flue was nice and hot without success then I thought "I wonder what happens if I try to run it with the sensor reading error?" Thankfully it seems whoever wrote the firmware was kind enough to allow the boiler to run with a farked sensor. The house is now toasty while I wait for my bits to arrive, just need to keep an eye on the boiler to make sure its still alight and not full of sawdust.  

[pottsiwebber]

So I got the new feed screw in the post yesterday, spent a couple of hours last night removing the old screw to fit the new one only to find it was 10mm too long! 

I took a couple of photos to compare the old with the new (reconditioned) screw, as you can see theres a bit of a difference! My old screw is 520mm long and it should be 555mm. No wonder the pellet feed is a bit iffy.




I've just returned from the shed after cutting and grinding 10mm off the end ready to fit tomorrow. Watch this space... if anyone does actually watch this space...