memco mw 100 building pressure

[FitzyD]

I reciently installed a memco mw100 wood boiler using my oil boiler as back up. My wood boiler is building pressure and I can't seem to find the source. I have replaced both my expansion tanks with new, I have an extrol 30 on my oil boiler and extrol 60 on the mw100. When my oil boiler is running alone, the pressure is at or around 15lbs. When I fire up my wood boiler the pressure starts to rise with the temp to aprox 22-24 lbs and stays there. I have ruled out any leaks on my domestic water coils and any issues with my fill regulator. Any help would be greatly appreciated. Is this normal?

Thanks, FitzyD

 

[atgreene]

My Jensen that is tied to my oil boiler also raises the pressure when I build a fire. I'm not sure if it's normal, but it too does it.

 

[FitzyD]

I did add another expansion tank and the pressure dropped down to around 20 lbs. Heating well and no other problems. Maybe this is normal! Thanks for the reply.

FitzyD

 

[Blevesque]

This is normal, you will see 5-10 psi rise. By the way my parents have a Memco 100 that they have been running hard 33-34 years now.