Ok so my wife and I recently purchased a new home . With this home came a century classic outdoor wood boiler. Ok so the hot water at 195 degrees travels 40ft to the basement and arrives at 175 deg. Once in the basement it goes through a plate heat ex changer to the tank on a gas boiler with 3 zones. One zone is for the radiant floors . The second is for the baseboards living room only. These are both piped with 3/4 in copper. The 3rd zone is for DHW. This is piped with a 1.25 copper pipe to a superstor ultra indirect hot water tank. The problem is when the DHW is called for it draws the system down to 140 degrees . When this happens it brings on the gas boiler and the baseboards do not get heat. Mind you we still have 175 degree water entering the basement 10 ft from boiler. I am tired of my living room being 55 degrees and burring wood and gas to heat a tank of water. Any help would be appreciated .
indirect DHW
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I am sure there are many ways to pull this off, I think any way you go will involve some new work.....I had a similar situation, I removed the DHW zone out of the heating equation. I set up the Nyle Geyser to a separate tank for DHW only......Now my wood boiler with oil backup just deals with the heat load.....The NG heat pump stays on 12 months a year, after the heating season, it's just the N Geyser....Welcome...
Gene I have considered pulling the indirect HWT and installing a tankless system or possibly even a electric heater.
real gene I am using a taco sr504
Does the fact that the DHW is run with 1.25 in and the other zones are .75 matter or is the DHW suposed to be run with 1.25 copper?
real gene I am using a taco sr504
Does the fact that the DHW is run with 1.25 in and the other zones are .75 matter or is the DHW suposed to be run with 1.25 copper?
maple1
Minister of Fire
I would think that 20 deg in 40ft was excessive as well but what can or should I do about it . I think the 45 deg loss in the last 10 ft to include the heat ex-changer and the input to the ga.s boiler would be the bigger issue. I am thinking that the superstor ultra is going to find its way to craigslist .
Okay, there is a switch in the upper right corner of the Sr504, which is the zone 4 priority control. If your DHW is on zone 4, that's the likely cause. Turning it off makes all zones independent. The piping is not the problem, the superstor coil is 1.25", so that's why the supply is sized that way.
Perhaps this is a silly question, but how are you regulating the temperature of the radiant floor loop? It shouldn't be higher than 130-135°F...
real Gene, I am only using my taco for zones 1 and 2 and the DHW is zone 1. Could there be a problem with the superstor ultra. It is calling for heat about once every 2 hours and taking a half hour to come to temp. I am so confused.
it is being regulated by to circulation pumps to 2 separate zones via regulators. The water is going out to the floors at 100
Hmm, that doesn't sound right. How large is the superstor, and what is the aquastat on the superstor set for? At installation, my 40 gal went from chilly well water to 120°F in 15 minutes.
its an ssu60 I dont know whether that signifies the size. As far as the aquastat set point um yah I have no idea what that is or where or how to check it.
The SSU60 is... 60 gallons. A liitle less than half-way up the side should be a small control box. There's an immersion well there, and the box is the aquastat, which should have wires running back to the DHW zone on the Taco relay. The aquastat is almost always a Honeywell, because they're cheap, but semi-reliable.
If you take the cover off the box, there should be a little wheel and a pointer for setting the water temperature (not terribly fine control, or very accurate). It shouldn't be set higher that about 140° (and that's high for DHW). If it's set higher, it's possible that the exchange coil inside is coated in lime/minerals, and the previous owner kept turning it up if the hot water was running out.
If you take the cover off the box, there should be a little wheel and a pointer for setting the water temperature (not terribly fine control, or very accurate). It shouldn't be set higher that about 140° (and that's high for DHW). If it's set higher, it's possible that the exchange coil inside is coated in lime/minerals, and the previous owner kept turning it up if the hot water was running out.
(Deleted my last post asking lots of questions, because I think there's only a couple:
1. What is the temperature of the return to the wood boiler?
2. Is there a wrap-around pump continuously circulating the water from the wood boiler through the gas boiler (see attached PDF from Century)?
1. What is the temperature of the return to the wood boiler?
2. Is there a wrap-around pump continuously circulating the water from the wood boiler through the gas boiler (see attached PDF from Century)?
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maple1
Minister of Fire
You can't do it right now, it's a summertime job - but the underground piping needs replaced with a better product. Most of your boiler heat is going into the ground - both coming & going. Which might be an underlying issue to your present problem - not enough heat is making it to your indoor boiler when everything is calling for heat.
What are temps like in & out of both sides of the plate exchanger? I would suspect also that it might be dirty & need flushing.
Where exactly is the 45deg. loss in 10 feet that you mentioned? DWH is a fairly small demand overall on a heating system. First thing to do would be see what the Superstore is set for and the tank temps, as mentioned above. Then get more temp data at all your ins & outs.
BoilerMan
Minister of Fire
When you say last ten feet can you take some pictures of your setup. There is no such thing as too many pics of a boiler system on here.
TS
TS
Why don't you give us a video tour of your system? Something is screwy.
Base on what I've read, I'd start by replacing the underground lines. They must be inches from the surface, and not insulated. In the meantime, I might try getting some 4'X8' rigid foam insulation, digging down to the lines, laying it flat on top, and putting dirt on top of them. You can recover the insulation this summer, and do the job right. If you don't want to dig, just lay the insulation on top of the ground, put a sheet of plastic over it, and the cover it with a couple inches of dirt. For 40 feet you only need five sheets, and surely you can find a place to use them after you recover them.
Base on what I've read, I'd start by replacing the underground lines. They must be inches from the surface, and not insulated. In the meantime, I might try getting some 4'X8' rigid foam insulation, digging down to the lines, laying it flat on top, and putting dirt on top of them. You can recover the insulation this summer, and do the job right. If you don't want to dig, just lay the insulation on top of the ground, put a sheet of plastic over it, and the cover it with a couple inches of dirt. For 40 feet you only need five sheets, and surely you can find a place to use them after you recover them.
JP11
Minister of Fire
One thing is CERTAIN... if you take lots of pics. Listen to advice and proceed slowly... the guys on this site WILL get you squared away. They may make you spend a little money. But take the pics, make the fix!
JP
JP
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