Pelletsbrännaren använder för mycket pellets!

[Edwardface]

Hej alla, jag hoppas att någon kan hjälpa till. Jag har en pelletsbrännare (ep-18a - https://www.altbergsplat.se/produkter/pelletsbrannare) och den bränner för många pellets. Jag får igenom 3 X 16KG påsar per dag.
Pelletsbrännaren är kopplad till en ATMOS DC30SF vedpanna. Den är ansluten till en Borö TIV 500L/FC110 som i sin tur är ansluten till en annan TIV-500L. Det sitter en Laddmoat 21 mellan pannan och tanken som jag har bytt termostatventil på.
Något måste vara fel någonstans eftersom vi inte ens använder det för att förse oss med varmvatten, det borde bara användas för radiatorerna men det slutar aldrig att gå.
Jag har ställt in temperaturen på pannan till 80ish och pelletspannan stängs av när den når det, men bara i 240 sekunder som ställs in på pelletsbrännaren och inte kan ändras. Den tänder sedan upp och kör ett tag, skölj och upprepa.
Röret som går upp till expansionskärlet på vinden är väldigt varmt (70 grader Celsius minst), så det känns som att istället för att stänga av sig själv så fortsätter den bara att gå och gå, vilket värmer upp vattnet i expansionskärlet på vinden.
Jag har försökt ansluta pannan till en timerbrytare så att den är på i 2 timmar och sedan av i 4 timmar, men även det använder fortfarande 2 påsar per dag, och innan de 4 timmarna är slut kan vi känna att temperaturen sjunker.
Jag har en granne som jag pratade med om hans pelletsbrännare och han använder 3 påsar i veckan, och han använder den också för varmt vatten så det måste vara något fel. Alla råd skulle vara bra. För tillfället kostar det oss 269SEK per dag för uppvärmning.

I live in Sweden but only speak English so I have just translated this, I apologise if it's a bit broken.

[Stegatorparn]

I don't know much about this burner, but I'll try to help you anyway. I'm pretty bad at English, so I'll use Google.
2-3 bags per day doesn't sound completely abnormal at this time of year. The size of the house, how well insulated it is and where in the country it is located are decisive for consumption.
The burner can be operated with electric start, the burner starts when the thermostat calls for heat and turns off when the thermostat turns off, or maintenance firing, the burner reduces power so that the fire does not go out and then quickly returns to normal operation when the thermostat calls for heat.
Judging from your description, your burner is operated with maintenance firing, which is not optimal for operation against accumulator tanks. The reason may be that the ignition is not working. Try switching to electric ignition if it works. Should you save some pellets in any case.
Is the burner controlled by a thermostat in the boiler? The burner should be controlled by a thermostat in the tanks for best operation.
It is normal for the expansion pipe to become hot. Any waste heat will benefit the house.

[Edwardface]

Jag kan justera temperaturen på pannan, vilket borde säga till pelletsbrännaren att stänga av. och det gör det, men bara i 4 minuter, varken mer eller mindre, sedan startar det igen. när den är påslagen står det ”Elstart” så jag tror att den körs med den elektriska startinställningen snarare än underhållsläge, men jag vet inte säkert. Jag antog att den skulle stängas av när den når den temperatur jag ställt in, och sedan slå på sig själv igen när temperaturen sjunker med 15 eller 20, men den slår alltid på sig igen efter 4 minuter även om temperaturen inte har ändrats. Jag undrar om det skulle vara bättre att ha expansionstanken i källaren istället för den oisolerade vinden? Jag tror att jag förlorar mycket värme genom vinden. Rören som leder till expansionskärlet är minst 30 grader varmare än mina radiatorer, det verkar som ett enormt slöseri. Jag har också mejlat företaget som tillverkade den för att se om de kan hjälpa till, men har inte fått något svar än. Det är konstigt eftersom den som finns på hemsidan inte ens är den nyaste modellen, så instruktionerna på hemsidan är gamla.

[Stegatorparn]

It seems like the burner does an "Electric start", but then it should take at least 4 minutes for the burner to burn down and go out and then 5-8 minutes to start up again I think.
The burner thermostat on the boiler, is it a thermostat in the panel or is it a separate one mounted in a dip tube?
Thermostats for regulating fans or pumps have a small hysteresis of about 3-5°. which could explain a quick restart. There are no mechanical thermostats that have a hysteresis of 15-20° as far as I know.
Are the accumulator tanks fully charged when the burner turns off?
How is the charging pump in the Laddomaten controlled? Setting?

I think the problem is that the burner is controlled by the boiler temperature.
A quick fix could be that the charging pump starts at 60° at maximum speed.
Standard thermostat in the Laddomaten is usually 72° or 78° when burning wood.
If there is a 78° thermostat in the Laddomaten, the burner thermostat should be raised to 85°.

Ideally, the burner should be controlled by a thermostat in an accumulator tank. A suitable thermostat can be Ekontroll's TK1B
https://ekontroll.com/tk1b

It is possible to replace the expansion vessel in the attic with a closed vessel in the boiler room. In this case, a safety valve dim 25 must be installed in the boiler's outlet for the expansion line and an outlet pipe from the valve to the floor.
A closed expansion vessel with a volume of 150 liters is connected to the boiler's return connection to get the lowest temperature possible.
The disadvantage of this solution is that the rubber membrane in the vessel has a limited lifespan and that the entire vessel must be replaced after 10-15 years.

[Edwardface]

"The burner thermostat on the boiler, is it a thermostat in the panel or is it a separate one mounted in a dip tube?" - I believe it's in the panel, or at least it's in the boiler not in the tanks.

"Are the accumulator tanks fully charged when the burner turns off? / How is the charging pump in the Laddomaten controlled? Setting?" - The tanks are charged when the burner switches off. The Laddomat has a thermostat valve with an operating temperature of 78°.

"I think the problem is that the burner is controlled by the boiler temperature.
A quick fix could be that the charging pump starts at 60° at maximum speed.
Standard thermostat in the Laddomaten is usually 72° or 78° when burning wood.
If there is a 78° thermostat in the Laddomaten, the burner thermostat should be raised to 85°." - I was thinking the same thing. as I'm not using it for hot water maybe if i replace the thermostat valve in the laddomat with a 63° one, then it wont need to get as hot. But im not sure we if it will be the same when everything is set to the lower temperature. Will it reach 65 then switch off for 5 minutes, then back on again? because then im in the same situation, but just at a lower temperature.

The tanks are a combined 1000l of water, plus whatever is inside the boiler, pipes, and expansion tank. Do you think this might be too much for a pellet burner? I understand the more the better with wood as it's manual, but is that the same with pellets? I was thinking that I might remove one of the tanks and then put a new 150l expansion tank in the basement.

I should also mention that we're currently only using the ground floor so all the radiators upstairs are off, cold. I was also thinking that this might cause issues, as the heat that should stay in the tanks can move to those radiators that aren't part of the circulation. In my head im thinking that if it's cold then it isn't costing me anything, but now im thinking that because it's not all hot, the cold parts are pulling my heat away from where i want it.

I really appreciate the help with this.

[Stegatorparn]

"The tanks are charged when the burner is turned off."
Something is definitely wired wrong. The charging pump should start when the boiler temperature has reached about 70° and should be controlled by its own thermostat. In an emergency, you can connect it so that the charging pump starts and stops at the same time as the burner, but then a lot of heat can remain in the boiler after stopping.
It may be a good idea to install a 63° thermostat in the Laddomaten, so the tanks are charged faster.
The Laddomaten's thermostat cannot affect the boiler temperature or the burner control. Its only task is to mix hot water from the boiler with cold water from the tanks so that the return water to the boiler does not fall below 78°/63° depending on the thermostat. If the return temperature falls below 60°, there is a risk of condensation of flue gases in the boiler, which causes tar formation and corrosion that shortens its efficiency and lifespan.

The tank volume determines how often the burner needs to run to charge. I have a 500 L tank myself and it is more than enough here on the west coast.
If you are going to turn off a tank, only close the valve at the top of the tank. The valve at the bottom of the tank should always be open for pressure equalization.

A radiator valve that is closed prevents the circulation of hot water. Just be careful so that there is no risk of frost if it gets really cold outside.

I think you should have an electrician check and possibly adjust any faults in the boiler's electrical system as well as pumps and thermostats.

[Edwardface]

okay. I'm only able to switch off the extra tank at the bottom, there is no valve at the top of the 2nd tank. Currently while i have everything on a timer, the water in the top of the first tank reaches about 80° and then the top of the 2nd tank starts to increase. The bottom thermometers on both tanks read about 40°

You say the "charging pump", is that the pump on the laddomat? That gets its power from the boiler, it never switches off unless the boiler is switched off, and the boiler needs to be on for the pellet burner to work. That pump is constantly running.

I thought that the laddomat keeps the water in the boiler circulating until it gets to 78°then the valve inside opens and allows cold water from the tank to come into the laddomat, which pulls hot water from the boiler into the tank? that lowers the temperature so the valve closes again until it gets back up to 78°. while this is happening the thermometer on the boiler is saying around 80° and once the tanks are charged everything rises up to about 85° at which point the pellet burner switches off.

I think i need an expert to come and take a look. It's unfortunate that the local "heating expert" who suggested the burner, has wired it up wrong. The problem I have is that because it's so expensive to heat during the winter, I cannot afford to pay a professional to come here. Especially as the professionals im already talking to don't seem to know what they're talking about, but are still happy to take my money...

[Stegatorparn]

I have obtained data on your boiler Atmos DC 30 SF and the water volume is only 58 liters. That explains why the burner restarts after only 4 minutes when the Laddomaten pump runs all the time. There is a rapid turnover of the water in the boiler.
It is absolutely correct that the burner gets its power from the boiler. There should be an overheating protection that cuts the power if the temperature goes above 95° and prevents boiling.

What needs to be done to correct the problem of frequent starts and stops is to install a thermostat that controls the burner in the first tank, for example the one I linked to. The sensors are inserted where the thermometers are. Then the burner starts when the heat starts to run out at the top, say 40° and stops when the bottom has heated up to about 60°-70°.

It is a waste to have the Laddomaten pump running all the time. It should be connected so that it runs at the same time as the burner.

You can close the valve to tank no. 2. The main thing is that the circulation is prevented.

[Edwardface]

Okay that's great thank you! I will get one of those and see if my heating engineer will come back and take another look at the wiring. I appreciate all of the help with this!