Just wanted to post some thoughts I got from another website:
I haven't really tried seeing if leaving the door open brings the temp up fast, usually its way down by the time I see it and I'd have to leave the door open for a long time, which cause the boiler to boil out some water and some good sized flames and smoke to pour out the door. I believe the fan/damper is operating fairly well, if I shut the door almost all the way, I can watch the fan stoke the fire really well. Is burning a crosote log okay for the OWB's? I thought I had heard they're not great on the system. I'm going to look into getting a brush system so I can sweep it this weekend, do I have to completely shut down the fire to do this, or can it be swept while operating?
Regarding the water side of the system. I don't have a definitive answer regarding whether or not the OWB temp stablizes when the home isn't drawing a load. Temps have been on the warmer side (40 ish degrees) the past few days but the boiler still falls to 150-155 degree levels, I can't believe my house is calling for the same load as it was when temps were -7 last week. I'm not trying to say that there isn't an issue with the home side, but I just don't know what would have changed that drastically. The guy I had perform the service on my system a few weeks ago said my system is very similar to ones he's installed, and a very common setup. I have a hard time believing that the past two owners were completely fooled by the system and lied outright to me about how it performed.
Quote Originally Posted by ...... View Post
I finally went back through all the prior posts to understand the details. Not sure I understand it all correctly. Below are a few thoughts based on what I think has been described.
First, I am commenting only on the air flow here. Correct me if I'm wrong. Damper opens at 175 boiler water temp, then boiler water temp proceeds to drop to the 150 range and take a long time to increase to the 180 closure set point. If you leave the boiler door open a crack then it heats fine, fire cranks up and boiler water temp doesn't fall into the 150's? You can crack boiler door, get fire cranking, maintain good boiler water temp, then close the boiler door and have the boiler water temp fall significantly despite the damper open/fan running? If these scenarios are correct, then you have an air intake issue. The damper open and fan running should not allow the boiler water temp to drop off like that if you have good coals and good wood in the fire box. When the damper is open and fan is running you should have high output from your chimney. Check it. Open the boiler door a crack and check to see if there is a difference in chimney output. This will isolate airflow to intake only and let you know if that is an issue. If opening the door does not make much difference in chimney output, then you need to determine if the chimney out put is adequate/proper. How much smoke is coming out the door versus exiting via the chimney? Its possible you have something in the chimney. Burn a creosote log and clean it out. Use a chimney cleaning brush and make sure there isn't blockage.
Second, I am commenting only on the home system heat draw. If I understand your diagram and descriptions, your owb-side water flow has been checked and is now fine. The owb-side water is running in a continuous loop and passes its heat to the in-home system loop through heat exchanger. Your in-home loop is not running continuously and while its idle the owb water temps are fine. Its only when the in-home is activated and running that the owb water temps drop significantly. Is this all correct? If so, the in-home system water temp running through the heat exchanger is cooling the owb water temp, so the in-home system is dominating the owb system. If true, it seems you have a design flaw in the system.