exhaust temperature
Verfasst: 17. Nov 2020, 12:21
Hi, I am from Canada (Newfoundland) and I speak English but I am still hoping that with people on the forum may be able to help me. Luckily I have been using google translate to read the forum and have learned a lot of information. I can't remember how I came accross the forum but I am glad that I did. The forum and members share a great wealth of knowledge!
I installed a walltherm (Zebru I think) about 3 years ago. My thermal storage is a logix24 tank. I am using a k36e boiler charging set which is installed next to the tank about 15'-20' away from the walltherm. I usually burn every second day and get good charging in the logix24 but it did take some practice.
The boiler charging set has a built in mixing valve set to 60C and is using a grundfos alpha 2 pump. My chimney is greater than 20' as was required by the installation manual.
When originally installed, the boiler came with a dial thermostat installed at the heat exchanger. I was told by the distributor to set this to 70 C so thats what I did. I adjusted the pump speed so that temperature in the water jacket was constant. I noticed quickly that sometimes the pump would run all night after I fired the boiler. This would destratify the tank and the stove just became a radiator which bled the stored energy from the logix24 and deposit it back into the living room. I quickly realized that I needed a differential control so I installed a Steca 501. I set the minimum boiler temperature in the Steca controller to 70 C as was the setting on the old thermostat.
Because our house is a passive house (http://flatrockpassivehouse.blogspot.com/) I opted for the quick panel insulation to cut down on heat in the living room. Because of this, the supplied stove pipe thermometer was unable to be installed. I just installed it this past weekend. I tested the thermometer in ice water and in boiling water to verify accuracy before installation. The thermometer is installed about 6" above the location of the original flue gas thermometer. I lit the stove and went through a usual slow warm up (about 50 minutes) and then flipped the gasification flap. The flue gases started decreasing in temperature...but I expected them to go much lower. Instead of dropping to 150 C as expected, the gas temperature was about 230 C- 240 C. Following the troubleshooting section of the manual, I expected that the flap seals had to be replaced. I had not replaced them for 3 years. I inspected them and they looked a little compressed but not too bad. However, I decided to replace them anyways. I lit the stove again yesterday and expected to see an improvement....no improvement was made. I am now thinking it is not the flap seal. The seal looked fine before replacement and the new one looks even better. When I turn the flap, I can feel that it is sitting in the right position and hear a soft "thud" as it seals against the rope gaskets.
I clean the stove daily, weekly and monthly. Daily, I empty the ashes, clean the grates and the glass doors, monthly I remove the grates, the injector, the flame wall, and clean any debris. I clean the heat exchanger and the back bypass monthly, but there is only fine carbon soot stuck to the heat exchanger. The exchanger bypass at the back of the stove is set at it's lowest position.
I am now thinking I have something setup wrong during the commissioning of the stove and I am wasting alot of heat. Do any of you have any ideas about what I should check or what I may have set up wrong?
Thanks
DJG
I installed a walltherm (Zebru I think) about 3 years ago. My thermal storage is a logix24 tank. I am using a k36e boiler charging set which is installed next to the tank about 15'-20' away from the walltherm. I usually burn every second day and get good charging in the logix24 but it did take some practice.
The boiler charging set has a built in mixing valve set to 60C and is using a grundfos alpha 2 pump. My chimney is greater than 20' as was required by the installation manual.
When originally installed, the boiler came with a dial thermostat installed at the heat exchanger. I was told by the distributor to set this to 70 C so thats what I did. I adjusted the pump speed so that temperature in the water jacket was constant. I noticed quickly that sometimes the pump would run all night after I fired the boiler. This would destratify the tank and the stove just became a radiator which bled the stored energy from the logix24 and deposit it back into the living room. I quickly realized that I needed a differential control so I installed a Steca 501. I set the minimum boiler temperature in the Steca controller to 70 C as was the setting on the old thermostat.
Because our house is a passive house (http://flatrockpassivehouse.blogspot.com/) I opted for the quick panel insulation to cut down on heat in the living room. Because of this, the supplied stove pipe thermometer was unable to be installed. I just installed it this past weekend. I tested the thermometer in ice water and in boiling water to verify accuracy before installation. The thermometer is installed about 6" above the location of the original flue gas thermometer. I lit the stove and went through a usual slow warm up (about 50 minutes) and then flipped the gasification flap. The flue gases started decreasing in temperature...but I expected them to go much lower. Instead of dropping to 150 C as expected, the gas temperature was about 230 C- 240 C. Following the troubleshooting section of the manual, I expected that the flap seals had to be replaced. I had not replaced them for 3 years. I inspected them and they looked a little compressed but not too bad. However, I decided to replace them anyways. I lit the stove again yesterday and expected to see an improvement....no improvement was made. I am now thinking it is not the flap seal. The seal looked fine before replacement and the new one looks even better. When I turn the flap, I can feel that it is sitting in the right position and hear a soft "thud" as it seals against the rope gaskets.
I clean the stove daily, weekly and monthly. Daily, I empty the ashes, clean the grates and the glass doors, monthly I remove the grates, the injector, the flame wall, and clean any debris. I clean the heat exchanger and the back bypass monthly, but there is only fine carbon soot stuck to the heat exchanger. The exchanger bypass at the back of the stove is set at it's lowest position.
I am now thinking I have something setup wrong during the commissioning of the stove and I am wasting alot of heat. Do any of you have any ideas about what I should check or what I may have set up wrong?
Thanks
DJG