Wood Boiler Issues and I need Some Help

[russsmit]

Here is what I have for a system and I need some help on a few issues.

I have a 130k btu Dumont Tempest Boiler (1980 Vintage). It was used for about 10 years and then unhooked for many years...so it has lots of life left in it. In fact I used it to heat my pool 2 summers ago as a test run. Works good. These were meant to run hard and burn fast as it has a 1/3 hp induced draft/forced air combustion system...and store the water in a tank or tanks for when it is needed. It came with three 330 gallon tanks for storage.

I have a finished cellar, no chimney (oil boiler power vented) and no room to use these tanks as storage. I happened to come across a Senco 110 gallon hot water storage tank and it has an internal coil. So I do have about 150 gallons of storage.

So I put the boiler in a small shed out back of my garage. Piped up the boiler to the Senco tank. Now my garage had a heating zone in it from the oil boiler so it was simple to turn that into a supply line to the existing oil boiler inthe house. I hooked that line up to the Senco tanks heating coil. The Dumont wood boiler heats the 150 gallons pretty quickly and I have set up circulating pump to circulate the water from the house to the Senco tank to use the heat stored in the tank.

Issue #1. The wood boiler pressure relief valve will release the wood boiler water when it gets up to its rated capacity...30#s I think. Anyway the PRV works as it should...however it works to often. I do have a small expansion tank on the system. Do I need more expansion tank capacity?

Issue #2. When I turn down the oil boiler settings the family complains of cold showers. I have a Dynatherm oil boiler. It has like a 2 gallon hot water capacity for domestic hot water. I am able to heat the house with the oil boiler turned down...but when it comes to morning showers the settings are too low. Now if I turn them up to 160-180 the oil boiler will run too often for my liking when I am trying to run the wood boiler. I am thinking of adding an electric hot water tank to the outlet of the domestic hot water line to store hot water and for it to top off the heat a bit if necessary via electricty. Will this help with my hot water problem?


Oh the Dumont is built to run as an unpressurized system...but many boilers are pressurized and I attached it to a Senco hot water tank rated for storing pressurized water...so I dont think I have an issue with that.

I am looking for some help on the two issues above. Has anyone set up a similar system? How did it work out? I am looking forward to yopur assitance.

 

[steam man]

It sounds like you don't have an adequate expansion tank on your system. How many gallons of water does the sytem have and what size expansion tank do you have? I would think the boiler should cycle down on high temperature. Does the fan shut off before the relief valve blows?

Issue two sounds like you need an indirect hot water tank with sufficient capacity for the family. A cold boiler with a tankless coil is not going to satisfy the family. The oil boiler could be set up with outdoor reset or even just a cold start possibly.

Where are you located? It sounds like you might be right next door. I live in Millinocket.

Mike

 

[russsmit]

Yes I live in Millinocket too. I figured out after reading some of your posts that you must live nearby to Millinocket as well. I currently have about 150 gallons of storage and just a 5 gallon expansion tank. So I think the obvious is to add a larger expansion tank or to depressurize the system and make it an open system. No the fan doesn't shut down on high temp before the valve blows. ANd the valv doesn't really blow...it just starts to trickle out...and it was a new valve.

I'm not sure about adding an indirect tankless heater to this system because of the expense...as the oil boiler satisfies our needs with the settings at the regular temps. I have the electric hot water heater (it cost me nothing) and an evening with the torch and a a roll of solder will integrate it into the plumbing of the boiler. I was thinking that the oil boiler heats the water and its stored in the tank of the electric heater and the electric heater maintains it at the temp we want..no huge Delta T for the electric hot water heater.

PM me if you'd like. My email is on my profile. Thanks Mike!

 

[steam man]

It looks like the expansion tank is way too small. I have 160 gallons of DHW storage and have a good size expansion tank installed. Also, I have set up circulates DHW through a 120g tank. It sounds like you need something similiar. Piping the tankless coil to a storage tank would work. You'll need an aquastat and a bronze pump in order to create storage. Not too big a deal. The plus side of the electric element would be a good backup/summertime use.

I sent you a PM.

Mike