Bock Hot Water Heater Flue Temps

Hi,

I have an oil fired Bock hot water heater. The flue pipe runs into a standard chimney inside my basement. Anyway, I notice that when the water heater fires that the flue pipe is way too hot to touch. I'm feeling that lots of heat is going up the chimney. Is this normal. I have a baro on the pipe but it doesn't move and is cracked slightly. Any ideas or advice.

Oil (or gas) fired hot water heaters exhaust do get very, very hot. Probably not a lot you can do, that is way many are designed, the heat just goes right up the middle,

They do make better fuel efficient ones, where the exhaust is piped up/around the tank to reduce the heat exhaust output and lower the temps and actully just use PVC pipe, but are very, very pricey.

here is one with a cutaway view and you can see how the exhaust extracts as much heat as possible before exiting
http://www.americanwaterheater.com/products/pdf/lpg100.pdf

If it really cold outside, you baro may open a bit due to the fast heat rising up the chimney and creating more draft, but most of the time, the baro's, if adjusted correctly, normally remain pretty stationary. All depends on the construction of your chimney.

Thanks for the info. I guess they designed these heaters when oil was cheap. I checked out the heater link and am impressed that 95% of the heat goes into making hot water. The only caveat was that the system shown in the link is for gas. Do you know if they make an oil fired version?

Looks like yours is one of the only other ones to be higher efficency, but maybe you can get it any higher with oil fired. ??

Maybe add a hot water coil to you coal stove and supplement your hot water.

I have a 48ft. ss 316 coil in my stove now. The water from the boiler runs through the coil in the stove and this setup does a great job of heating my basement. The stove does the upper two floors without any problems. I have another coil in my boiler and installed a circulator so the coil will circulate the hot water in the hot water heater through the coil in the boiler. This should help to take up some of the load. I would like to find a replacement hot water heater to replace the one I have.

Trader I have a Bock oil fired water heater 40 gallon with their direct vent. When running I can't put my hand on the exhaust pipe, it's just way too hot. I think mine has about 85% efficiently.

Adam: I wonder if you put a rheostat and a smaller nozzle ifyou could keep more heat in the tank. The recovery time would suffer but I would guess you might burn less oil.

My oil furnace stack gets up to 300* during a long cycle. It was new in 1996, 85% efficiency. From what I understand, 85% is about the best you can do on oil. If you want percentages in the 90's, then you'd have to run gas.

Trader I have a Aero 30 gallon oil-fired water heater, it's called a lowboy, the combustion travels around the tank and it has a side vent. I bought it because of clearance issues, but I feel it is more efficient then the heaters that vent up through the middle of the tank. Aero has since been bought by Bradford-White.

Alaska Kast Console Is Home

traderfjp wrote:Adam: I wonder if you put a rheostat and a smaller nozzle ifyou could keep more heat in the tank. The recovery time would suffer but I would guess you might burn less oil.

Where would you connect a rheostat to system like mine and how would it work? We put in 3/4 of a tank of oil for hot water for the summer and our tank is just now a little past the halfway point. It doesn't seem like we have been using that much oil at all for just heating up the hot water.

It sounds like u are burning a lot of oil for hot water. I bought 500 gallons and I seem to be using 10-20 gallons per month. I replaced the Carlin head with a new Beckett head last year so maybe that helped. I was going to buy a Reillo but they are harder to setup. I'm not sure if this would work but I have a rheostat on my direct vent motor. It allows me to reduce the motor so the heat stays in my coal stove longer. I think we are losing a lot of heat because these tanks have such a high recover rate and fire at a high level. I was thinking of putting in a smaller nozzle in my burner but I'm not sure I would gain anything.

Bock water heaters and all oil fired water heaters are not that efficient.You can take the smoke pipe off the top and clean the fins(lots of them in there).MOST heating guys don't do this.On some bocks there is a tube in the middle of the fins to slow down the flue gasses .Some heating guys take them out so the heaters don't clog up so fast(bad idea)
DON

Don: You know your heaters. I actualy took the center thingy out because I had too much back pressure. I probably should have just cleaned the unit and put it back in. I still have it so I guess I'll try re-installing it. Even with it in the flue pipe got really hot though. Do u have any suggestions for a replacement heater. Propane is an option too but I'm paying 5.00 a gallon for that.

I better I'm a plumber!
Find out what type of electric service you have.If it's a day night rate or not.If it's not forget electric.Unless you're at .06 cents per KW.

The new propane high eff.water heaters are great.90 or 95%.5.00 a gal. is a lot for propane I would shop around.They are so eff.that you vent them with PVC pipe no kiddin.
DON

Cool stuff. My Bock is about 16 years old and I changed the anode rods last year. There wasn't much left to those anode rods - I should have replaced them long ago. The burner head is only about a year old. I may be pushing my luck but I figured that next year I may change the tank out or go with a different type of fuel. You would get a kick out of my Utica dry base boiler. That sucker is about 35 years old. I clean it yearly and last year I re-insulated everything. Now that I have a big coil in my coal stove I pipe that through my boiler and the boiler rarely turns on. It just has to heat the basement. NY has one of the highest electrical rates so I'm not sure if an electric tank is worth it.