New Biomass 40 combo owner with questions

[hoyt144]

Hi everyone, Ive been lurking here a while and have finally been able to get my boiler set up. I will admit Im a complete newbie and would appreciate any hand holding available. I had a local plumber do the install and while I think its set up mostly correct Im sure there are some tweaks that will help. It is currently set up with 820 gall un pressurized storage tank. My first question is with the boiler itself. When the boiler attempts to switch to oil it is puffing back through the air intake on the front and eventually the burner will shut off and need to be reset. Im not sure if this is a burner set up issue or something else. The other issue or more question is how does the controls for the tank circulators get done. I have the aquastat recommended by Tom at AST but as its wired now I dont think its controlling the pumps as intended. As it is currently when a zone calls for heat the primary loop circ and tank circ come on with the zone pump. While this works if the boiler is running on wood and there isnt a zone calling for heat I want to be able to charge the tank correct? How should this be wired in a perfect world......

Thanks for all your help
Mike

 

[NateB]

I think we need more details on how your system works before we can help with your design. The question I would have is can you keep the tank circulator off when you are burning oil?

I think your primary loop circ should stay on all the time, and your tank circ should only come on if:
1: there is a call for heat and the tank has heat
2: there is excess heat in the system that is ~20 deg hotter than the tank, and you are burning wood.

...but I need more information before I can give you a good answer.

 

[hoyt144]

As it is right now I have only had the system operating for 3 or 4 days and have yet to get the oil to operate for more than 10 seconds at a time. I agree that I want the tank circ off when on oil. So the primary pump should be running all the time regardless correct? I have a honeywell L6008A aquastat but im not sure its set up correctly at this point.

 

[NateB]

https://www.hearth.com/talk/threads/primary-secondary-piping-for-boilers.11837/

Does you primary secondary setup look similar to image in Bob Rohr's first post?

 

[hoyt144]

It does look similar to that Nate, I can try to post a pic tonight when I get home

 

[NateB]

Ok there is sometimes confusion as to what the primary loop is. Yes the primary loop circ should always be on. As for the oil not staying on. It seem like either the circ is not coming on, or the flue may be blocked.

 

[hoyt144]

I did check chimney, it is clean. Havent had any issues running on wood. When the burner kicks on its not a steady smooth sounding burn. Its hard to describe it, its almost sounds like a thumping noise and the little flap for primary and secondary air intake is flapping

 

[NateB]

Hmm is the oil line blocked?

It looks like the boiler control closes a relay to start the oil burner, so you have to use that signal to keep the tank pump from coming on.

 

[hoyt144]

I wouldnt think its blocked. It was just installed and bled. I will rebleed the pump tonight and the plumber is coming back to finish install of the garage modine and I will be working with him to figure it out. Is it feasible to use the tank temp to control the circ for storage? Correct me if Im thinking about this incorrectly but if the storage temp is below say 140 the aquastat opens the circuit shutting down the pump so that the oil burner is only heating the other house zones. if the temp in the tank is above that then I want the tank circ to run....maybe. Overall I think he has the plumbing correct its just the controlling of this is where the trouble is.

 

[Bad LP]

I wouldnt think its blocked. It was just installed and bled. I will rebleed the pump tonight and the plumber is coming back to finish install of the garage modine and I will be working with him to figure it out. Is it feasible to use the tank temp to control the circ for storage? Correct me if Im thinking about this incorrectly but if the storage temp is below say 140 the aquastat opens the circuit shutting down the pump so that the oil burner is only heating the other house zones. if the temp in the tank is above that then I want the tank circ to run....maybe. Overall I think he has the plumbing correct its just the controlling of this is where the trouble is.

You can have two different set points for what heating source is being used. I'm using 120 for my tanks. At 120 on the storage tank it opens the control on the LP. Vice versa on the cool down. When below that temp the LP boiler runs like there is no other heat source in the building. 100% seamless operation.

 

[NateB]

There are controllers for solar hot water that do a good job at storing heat into the tank, and i use an aquastat to heat if the tank is hot enough. Your solution will be a little different because both your boilers are in the same unit.
You will need a normal closed relay to turn the tank pump off when the oil boiler fires

 

[hoyt144]

Just wanted to give a little update on the oil burner issues I was having. The installer pulled everything apart on the burner and found the cad cell had been installed but never plugged in and with a little fine tuning had it running fine. Still need to work on the controls a bit however.

Sent from my SM-G930V using Tapatalk

 

[NateB]

Good to hear it was something simple. Keep the updates coming, and maybe some pictures. Keep asking questions, I will do what I can to help.