Dump Zone question on Wood Boiler

Aidan (UK)

You won't get any circulation by gravity/natural convection unless there is heat being dissipated at the high point, the finned tube. Hot less-dense water rises, colder more- dense water descends. No cooling at high-level means no circulation.

The circulating pressure and flow-rate also depend on the height of the gravity loop; 6" doesn't sound adequate to me.

Set a fan blowing on the finned tube to see if that starts water moving; if it does, you'll know that's your problem.

Saggs

Just installed a wood boiler add on for a customer to work off his existing oil boiler. I installed a dump zone to operate off power loss or hi temp situation using a N/O zone valve. I did one of these before and it worked fine. This time I teed off the main supply B4 the exp tank and about 6" below the top of the supply header. The dump piping goes up to the ceiling (about 6") above the main header and works a loop thru finned piping and comes back into the wood return down low w/a swing check on the return. Cant seem to establish flow unless the wood return circ is running. Any help?

Derheatmeister

UPS..

No not united pacel service
How about using an UPS powerbackup battery pack in case the power fails ?

This will keep the circ. running for a couple Hr depending on the Amps required ,an 007 takes 0.7 amps

Gravity systems use large size Piping and over sized Heat emitters..

Saggs

Due to the low height of bsmt ceiling I can only get the finning so high, is this salvageable w/out having to install a circ and a ups backup? It would be a pain to run this up to the second floor. I understand what youre saying about the heat dissapation though.

jp_2

not the height

you really do not need to be much higher the the height of the boiler, more importantly is getting a larger change in temp to get the convective current flowing.

Saggs

That being said, I have seen people using large cast iron rads as heat sinks for dump zones but they are on the floor, lower than the boiler, will this work as piped?