Woodpellet boiler woes

lostinrates

bgprior wrote: »

1. Check if your installer claims to conform with the REAL Assurance Consumer Code (most of them carry the REAL logo on their website if they do). If you can't get a satisfactory response from them, refer them to REAL.

(Text removed by MSE Forum Team)

I agree with other comments. It doesn't sound like your problem is with the wood pellet boiler, but with the heat storage and distribution system attached to it. 28 kW should be giving you a lot more hot water than you are getting. Different wood pellet boilers may be more or less efficient, more or less reliable, and more or less automated, but it is unlikely that they cannot put out the amount of heat that they are rated for. Sounds like it's either not being called enough, or the heat isn't being exchanged efficiently enough.

We have a 70 kW wood pellet boiler for me and my two neighbours. Two large houses (four bathrooms each) and one cottage (two bathrooms). One of the big houses has very poor efficiency (listed building, singled glazed, minimal insulation), the other two properties are averagely efficient. No problems supplying all the heat and hot water for the properties, although each of us also burns logs to save a bit of money.

But watch out for distribution losses. They are much higher than the theoretical figures claimed by manufacturers and installers. I'm about to do a blog post on our website with the details, but in short, our ETA boiler is almost exactly as efficient as claimed (around 90%), but losses from there to each property are averaging 38.5% over the year, making a combined system efficiency of 55%! We have seen this sort of performance in some of our customers' systems too. If you have any significant lengths of piping and they aren't well-insulated (and likewise the buffer tank), you might be losing more heat than you realise. But I doubt that's the main problem in your case.

This is interesting.

We do have some lengths of exposed piping on the rather old radiator system (this system worked well on the old oil boiler) and the heat store is some distance from the boiler . Not a huge distance some twenty metres. The pipes run through the newly laid and insulated floor.


We have been reluctant to lag internal wall mounted pipes from an aesthetic consideration, and because it was not beyond the capability of a very old oil boiler. We were sold the system as it would simply 'attach to what you have and work'.

In anycase, it's been interesting to have other input. We are guided that our boiler is a very good machine, perhaps not best installed and borderline in appropriacy of size of the future house (what it was spec'd for).

The installers our now saying it may not be running at its optimum as their commissioning agent normally does this. We have asked the original installers to take a final opportunity to do this, but with the project manger/architect here and our independant expert. Certainly the independant advisor is of the opinion that we have been poorly advised by the supplier through out.

Canucklehead

Twenty metres of insulated pipe or just buried in an insulated floor?

Any luck finding those temperature blending valves yet?

Given all your advice so far I would hold back on the 'we are guided that our boiler is a very good machine' bit.

It'll be interesting when/if ,or ever, you reveal the details of the system.

lostinrates

Canucklehead wrote: »

Twenty metres of insulated pipe or just buried in an insulated floor?

Any luck finding those temperature blending valves yet?

Given all your advice so far I would hold back on the 'we are guided that our boiler is a very good machine' bit.

It'll be interesting when/if ,or ever, you reveal the details of the system.

I think just buried in an insulated floor. ( but I also think its less then twenty metres, I am being negative to the benefit of the system). We had suppliers ok the pipes before the concrete pour.

Originally the spec was to cover the place wit water filled underfloor heating.....presumably heat loss from that must be significant too? ( forgive female lack of understanding please!)


And yes, further along, when agreement is met at the end I will say what the system is, and if it's not seen as defamation, the installing company.

DaveWSmith

Hi , Ive just skim read most of the post, so Please excuse me if I have got it completely wrong. but something that seemed odd from your first description was the HW set up, We had our system nearly a year, after the original oil boiler (1967) died and the spares not available.

Our Wood pellet heats through the Coil in the 255 Ltr tank to heat the hot water, this also goes to the CH in Parallel .

As I understand it yours is using the CH tank heating the coil to provide hot water, so as the water passes through the coil it will heat the water, but also cool the tanks water, ( I presume the coil is at the top as that's the hottest spot) it will take longer to reheat the tanks water as it will continue to be pumped around the CH. this means that it would be loosing heat two ways, taking longer to reheat the tank which would in turn means less hot water. I'm also presuming that its a Pressurised system with no hot storage.

lostinrates

DaveWSmith wrote: »

Hi , Ive just skim read most of the post, so Please excuse me if I have got it completely wrong. but something that seemed odd from your first description was the HW set up, We had our system nearly a year, after the original oil boiler (1967) died and the spares not available.

Our Wood pellet heats through the Coil in the 255 Ltr tank to heat the hot water, this also goes to the CH in Parallel .

As I understand it yours is using the CH tank heating the coil to provide hot water, so as the water passes through the coil it will heat the water, but also cool the tanks water, ( I presume the coil is at the top as that's the hottest spot) it will take longer to reheat the tanks water as it will continue to be pumped around the CH. this means that it would be loosing heat two ways, taking longer to reheat the tank which would in turn means less hot water. I'm also presuming that its a Pressurised system with no hot storage.

Ours was originally plumbed as you describe yours. It didn't work effectively so they wanted to try the way they have done. And yes, you are right, heat loss is a massive problem, but it's marginally more effective than original way s for central heating alone for some reason.

lostinrates

Just to update this, the situation remains in dispute with mcs. A huge flaw with the complaints system is you cannot have third party work done on the system, so we cannot continue trying to get it to function.

I checked old photos and I was wrong about the pipe work, it IS insulated and the floor too is insulated.

I really cannot wait to have the process over with so I can name the company.

ModelCitizen

This is deeply worrying. Your situation is very similar to my own (except I have yet to place the order for my system). I have a Victorian detached house in an exposed area, very hard to insulate and with an energy efficiency value of a paltry 34. I have applied for planning permission to add nearly 40% to the floor area, bringing it up to 212.57sqm. The heat requirements of the building after the extension have been estimated at 26.5kw (inc hot water) and I have been recommended at 25kw boiler with 750 litre heat store accumulator (although I am considering an 855 litre one as it an additional coil for latter addition of solar heating). The boiler will be in the garage, 26m from the house. As I have the room it has been recommended that the accumulator is in the house meaning that the 32mm flow and return will travel 26m under my garden and another 7m under a wooden floor. The pipes will be run in a very fat black corrugated insulated pipe that costs £50 a metre.

I have been recommended a choice of three types of system:

1) The same as yours. As I was warned about robbing, and after reading your experience I have discounted this system, although the fact that only one big cylinder (accumulator) is required is attractive.

2) A heat store/accumulator and a hot water cylinder. The cylinder to be pressurised to provide me with mains pressure hot water.

3) A 'rapid heating' plate system. I have not understood what this is yet!

I am inclined to go with 2) as it seems the most traditional and should ensure that I have 250 litres of stored hot water hanging around most of the time. If the worse comes to the worst might installing a seperate cylinder be an option for you? With so many en-suite bathrooms you'll need at least a 350 litre cylinder I imagine.

BTW. Your private message facility is full so it's not possible to pm you.

lostinrates

Model citizen, I have deleted a couple of PMs so you can contact me. I am afraid my pm box is nearly always full.

As you may have read, our cylinder was meant to have coils for three sources of heat (our plan was the pellets, solar thermal and gshp, probably bore hole type when we extend. One of the plumbers explained this was not possible (though I have it on recording from the company that it is).

Our providers do the rounds of the trade shows etc, and do not seem to have a bad reputation. However, because of various personal reasons we luckily record most meetings here, so ave plenty of evidence of what we believed were sold and how it was meant to work. We were hoping to solve the problems amicably, as its more out style, but have no doubt on a review of the evidence we have, that our complaints will have to be upheld.


A word about it in the garage, ours is in a utility room, rebuilt to adaquatedimensions specifically to house it. Our chest freezer and dryer etc are also in there. While it SHOULD work there (not least as the dryer ensures that room is usually the warmest in the house this winter) we have for d on very cold days the boiler Just shuts off. Fails to work and will not reignite etc entirely. While the company routinely houses these in outdoor buildings inc metal sheds they blame this lack of function on that room being being too cold.

It was the one cylinder/tank that clinched this for us. It already takes up considerable space (and is bigger than dimensions provided by the company as they made no allowances for pipe work when we asked them for the requisite dimension (we also resigned the room this is in for this equipment, and had to have a very expensive door remade narrower and the hole for this door made smaller). It was on the basis of this being ok we went for this over a non pellet form of biomass burner. (Which a larger buffer/accumulator is totally requisite as I understand it).

A further personal issue which is making it all slightly harder to deal with is that I have a chronic health issue, and my medication changed last summer to one which produces quite seriously limiting side effects if I get too cold. While i prefer to be too cold than too hot by nature, and coped the last two winters with no heating adequately, having no reliable hot water for a bath when I have been working outside, and at times having no heating has been rather lifestyle limiting this year and very, very painful. I am grateful it has been a relatively mild winter!

The old smaller kw oil boiler we had in the house when we bought it coped fine, if uneconomically, so we re fairly sure it's not an issue to do with the house intrinsically being 'unheatable' .

It's all very dispiriting tbh. Unlike others we find ours needs a fair bit of time spent on it. The hopper needs refilling every second or third day, the ash pan emptying at least weekly (and then considerable clean up both inside and out side the boiler.

Our independent expert supported the suppliers claims that its a good machine, and he said it was actually one of the better ones he had seen (on paper) but that in situ it is obviously not performing as promised.

Sorry to sound so glum compared to others, but when it goes wrong, and it is the system or first in place element of an integrated system the impact is not inconsiderable.

lostinrates

Update.

The MCS took the complaint but then redirected it to the NICEIC. This process is taking a long time and is not following the protocol as laid out in the guidance by either one of these bodies. Regretfully we have escalated this to a trading standards complaint and are starting to prepare for a court case.

The bodies involved have been exceedingly pleasant to deal with but essentially ineffective. This is a concern for us. The procedure is simply to drawn out for something that is a pretty essential requirement.

lovesgshp

Sorry you are still having problems. I keep looking to see if you are getting any further forward. Had to change my user name, if you don't recognize it. Hope things get sorted very soon for you.