Just fired up my gasifier

[huffdawg]

The HX is only used for DHW and cannot be moved, as I understand the design of these tanks the HX am using for DHW are moulded around the bottom 1/3 of the inner wall of the tank.

On pipe insulation, the tank and boiler are located in an insulated room I built at one end of the carport. Once they leave there all water lines run through a 4" non vented flexible pipe under a wood deck and thru the crawl space to the root cellar.

I have the water level 8-10" above the draw for the heating loop, temp at the top of the water is normally between 160-170' and I haven't been able to find anything without spending an arm and a leg to check the temp lower in the tank. That being said with a hot tank I get 140' DHW and the electric water heater is set at 130'.

You can get a digital remote barbecue temp sensor fairly cheap. I guess flipping the tank upside down is out of the question? Is that non flex pipe insulated?

 

[huffdawg]

The pump launch is purely based on boiler temp, so it launches at 165' will run down to 145' and repeat until satified. Thus far have only been firing boiler once in the evening and once in the morning.

Sorry Dogshark, I was quoting a previous quote by Maple.

 

[Dogshark]

I would say you definitely need return temp protection previously mentioned, for starters.

What all is insulated?

Watched the burn cycle last night as was our first cool night in a while, it took the boiler quite a bit to get to run constant. In other words pump would start then stop when temp dropped below 140 heat back up and do it again until circulation temp got high enough. Checked it this morning and it was cycling 162 degrees. A temp protection valve isn't in the cards at the moment so would reversing the draw, pull from top of the tank and return to bottom help in the interim? My thought is that it would heat from the bottom up instead of from the top down which should be more efficient.

 

[maple1]

I don't think that will help the overall situation efficiency-wise. You usually would want to supply your hot water to the tank at the same level as your zones are drawing from (and they should ideally draw from the top), and you will lose any stratification. And actually, the water will potentially pull more heat from the fire if it is cooler entering the boiler - but that situation (return below 140) is usually a recipe for increased creosote condensation in the firebox (and increased corrosion potential), and will create the short cycling thing you're seeing. The return temp protection thing keeps return temps at 140 (until tank temps get above that), and make for a steady boiler operation. If you are contemplating cutting the piping to rearrange the supply & return, it should be a pretty simple think to plumb in protection - would only need a couple of Ts', a short piece of pipe for bypass leg, and the thermo valve. (And I guess ball valves for isolation purposes). Not sure what they cost - lots of people are using a Danfoss ESBE (I think I got that right), there are also Caleffi & LK valves available via site sponsors thru the banner ads. Here's just one example from a quick Google search which also happens to be a site sponsor:

http://www.smokelessheat.com/boiler-accessories/danfoss-thermic-mixing-valve

How's the creosote in the boiler?

Is your tank insulated?

 

[Dogshark]

I don't think that will help the overall situation efficiency-wise. You usually would want to supply your hot water to the tank at the same level as your zones are drawing from (and they should ideally draw from the top), and you will lose any stratification. And actually, the water will potentially pull more heat from the fire if it is cooler entering the boiler - but that situation (return below 140) is usually a recipe for increased creosote condensation in the firebox (and increased corrosion potential), and will create the short cycling thing you're seeing. The return temp protection thing keeps return temps at 140 (until tank temps get above that), and make for a steady boiler operation. If you are contemplating cutting the piping to rearrange the supply & return, it should be a pretty simple think to plumb in protection - would only need a couple of Ts', a short piece of pipe for bypass leg, and the thermo valve. (And I guess ball valves for isolation purposes). Not sure what they cost - lots of people are using a Danfoss ESBE (I think I got that right), there are also Caleffi & LK valves available via site sponsors thru the banner ads. Here's just one example from a quick Google search which also happens to be a site sponsor:

http://www.smokelessheat.com/boiler-accessories/danfoss-thermic-mixing-valve

How's the creosote in the boiler?

Is your tank insulated?

I am seeing creosote build up in the firebox, the rest of the boiler is good, I see a mixing valve in my future maybe after the holidays.

The tank is very well insulated on the bottom and sides, which is the reason I only fill the tank to 10" above the draw port for the heat. On top I insulated the tank externally.

 

[Dogshark]

Something else I noticed, was getting very clean hot burns for a few days. As the weather is temperate this year I shut it down and cleaned all the ash out, some fly ash in the secondary burn chamber and heat exchanger and a good bit of ash in the fire box. I noticed that in the ash on the bottom all but a 3/4" x 6" slot over the air manifold was closed up, cleaned it all out and fired it back up. Loading it up this morning I noticed the same pattern all closed up but for the same 3/4" x 6" slot but running very efficiently (clean air from stack, burns longer with less wood, and heats quickly). Is it possible for this thing to be trying to tell me something? My opening in the bottom of the firebox to the air manifold is 1" x 9", when I tapered the bottom of the firebox to be sloped I left a 3/4" x 12" slot in the firebrick directly over the 1" x 9" slot in the floor yet each time after I clean it out I notice this same pattern. Any thoughts?