Problems With KAA-2 Temps.

KLook wrote:Your boiler works on the same principle as the on demand water heaters. You can spit cold water through them at full speed and they heat it up. But it is pushed through small ports that get the water in contact with as much exchanger surface is possible and I guess they create condensation and have short lives if the water is hard.
Ours work on having large water storage and matching the flow(btu's/gal = flow/min) @ X temp. If you are feeding radiant heat, then you can circulate all the 140 water you want. If you are feeding baseboard, toe kicks, and cast iron like I am, you better have a min. of 160 and that is after some hotter stuff has already gone out and put out some heat where demanded. I have a radiant slab also but it is an injection system and always has enough heat in the water to work.

Kevin

Correct, which is why I went through the exercise of trying to determine what the OP's system would look like in the first minute of operation from a cold start.

If he's returning 150f water to the boiler, and if it's heating water at a rate of 1000btumin, then there isn't any reason, aside from poor boiler design, that the water in the system will ever drop below a low limit threshold of 150f.

Also, he's in the heating season, so while I used 86 degree water in the pipes, in actuality it should be higher because of the constant calls for heat.

The circulator on my boiler is capable of putting out almost twice the capacity of the boilereach minute. I don't think the boiler is that efficient.

To try to help the OP with things he can control to maximize the performance of a small boiler facing a big load, I would suggest:

- make sure a good quality coal is being used and that it is not excessively wet;
- use buck if it is permissible, and ensure the coal has few if any fines or undersized pieces;
- make sure the heat exchange surfaces of the boiler and the smoke pipe are clean;
- make sure the draft is set properly and that the baro is functional;
- make sure the feed rate is up to the max permitted by the manufacturer, or the max at which an orderly fire can be maintained, whichever is lower;
- make sure the fuel/air mix is optimal (i.e., produces no more and no less than the recommended ash band); and,
- make sure all gaskets and seals are in good shape so the combustion chamber isn't cooled by air infiltration.

Please add to the list anything within the OP's control.

Mike

kstills, I think your math left out the pickup factor for losses associated with the distribution piping that don't effectively heat the living space. I think Keystoker these days uses 1.18. In the olden days the manufacturers were a little more generous.

Mike

Pacowy wrote:kstills, I think your math left out the pickup factor for losses associated with the distribution piping that don't effectively heat the living space. I think Keystoker these days uses 1.18. In the olden days the manufacturers were a little more generous.

Mike

I was just thinking the same thing myself. That would account for an overall reduction in the ability of the boiler to heat the dwelling at design, if in fact the boiler output is only 60k instead of the 72k advertised.

Pacowy wrote:Please add to the list anything within the OP's control.

sure -- why not

1) Make sure the zone pump(s) or electromagnetic zone valve(s) are running or active while there is a call for heat in the load and-- AND while the boiler is above condensing temperature.

2) As previously suggested [by others] - be sure the system is circulating - check your supply and return temperatures for at least a 12% delta T - be sure the lines are not air bound!

Kind Regards
Sting

[quote="kstills] That would account for an overall reduction in the ability of the boiler to heat the dwelling at design, if in fact the boiler output is only 60k instead of the 72k advertised.[/quote]

Yes, as mentioned in my long-buried post on p3, Keystoker recommends a load of 400 s.f. of hw radiation for this unit, which translates to 60k btu/hr delivered to the installed radiation.

Mike

Everyone,go back to his beginning pics,look at the flue pipe,one of the things that need corrected in this system.Original poster has stated on page 8 that boiler gets to 180*,also on page 8 states that the boiler has no problem getting up to temp .I will stick to what I said earlier..get rid of the yo-yo start & stop ,up & down in this system.

Everyone,go back to his beginning pics,look at the flue pipe,one of the things that need corrected in this system.Original poster has stated on page 8 that boiler gets to 180*,also on page 8 states that the boiler has no problem getting up to temp .I will stick to what I said earlier..get rid of the yo-yo start & stop ,up & down in this system.

Thank you.

Kevin

I can't say if there may be better ways to control a boiler than the KS's supplied 8124, maybe so. If wired as they say, and set at 160*, as they recommend, it should protect the boiler from condensating temps. Too cold, the pump will not run, and the boiler will heat up quicker on a cold fire-up. Some guys don't seem to understand how important this is for the life of the expensive device. My point is to argue with those that seem to be advising to change the wiring and let the pump run, regardless of boiler temp.

I will admit that my C1/C2 terminals are wired to one side of a std rec'l box, the pump plugs into that side. The other side is hot full time in case of some emergency and I want the pump to run, regardless of what the 8124 tells it.

That said, although I am still in Oliver's camp on more idle pins, but I agree that air in the piping could be the big deal here.

Dave

KLook wrote:

I will stick to what I said earlier..get rid of the yo-yo start & stop ,up & down in this system.

Thank you.

Kevin

Can somebody please put into words how or why the start-and-stop of the circulator pump would have any meaningful effect on the BTU's the boiler is puts into the installed radiation and/or living space? Either you have an intermittent flow at the low limit setting or a continuous flow at a temp lower than that, but both would be carrying essentially the same btu's.

Mike

I guess it couldn't hurt to try jumping out the thermostat to keep the boiler running and wiring the circulators to run continuously. As long as someone is there to monitor constantly. If the boiler is at max fire, you would think eventually the house would warm up, even with the circulators running constantly.

Oliver and I are not asking to keep the pumps running constantly. We only want the pump running when the water is HOT. And by that we mean HOT, not 140 not 150 not 160. I don't care what Keystoker says about their recommended temp, we are outside of their recommended heat load.
Mike, BTU's are BTU's are btu's. But EFFECTIVE and USABLE BTU's are only found in the high end of the temp scale. When you circulate hotter water, more BTU's make it back to the boiler giving it a better chance to reheat to usable BTU's again. If you just warm it up, spank it on the ass and send it back out, you will get cooler water the second time around and on and on. Until the boiler and the load become stabilized and you are cold because the water is at 140. You must only put out the amount of water that you can reheat to a high enough temp to keep up. This varies according to FLOW and return temp(load).

Kevin

kstills wrote:

Rob R. wrote:Maybe we have a forum member in the area that can take a look? A stoker boiler guy with basic electrical skills should have this diagnosed in short order.

Farrell isn't going to be able to handle control changes, unless I misunderstand his posts. And it doesn't seem he's in a position fiscally to put much money into having someone fix it for him.

I am more than happy to pay someone to take a look at this for me. Money is not an issue. I have tried calling a few guys in the area and the ones who have got back to me refuse to look at coal.

I have also checked the lines for air. No air. what I hear is pinging from the aluminium fins when the circulator kicks in.

Pacowy wrote:
Can somebody please put into words how or why the start-and-stop of the circulator pump would have any meaningful effect on the BTU's the boiler is puts into the installed radiation and/or living space? Either you have an intermittent flow at the low limit setting or a continuous flow at a temp lower than that, but both would be carrying essentially the same btu's.

Mike

You are right about the total BTU's moved, but it doesn't get distributed throughout the structure the same way. Depending where your rocking chair is placed, and how air can move throughout the house, you may be more comfortable with steady flow.

Regardless, we have buried this poor guy with things to check and things to change. I think it is time to go back to the basics (and things that don't require a torch or sawzall).

Pacowy wrote:To try to help the OP with things he can control to maximize the performance of a small boiler facing a big load, I would suggest:

- make sure a good quality coal is being used and that it is not excessively wet;
- use buck if it is permissible, and ensure the coal has few if any fines or undersized pieces;
- make sure the heat exchange surfaces of the boiler and the smoke pipe are clean;
- make sure the draft is set properly and that the baro is functional;
- make sure the feed rate is up to the max permitted by the manufacturer, or the max at which an orderly fire can be maintained, whichever is lower;
- make sure the fuel/air mix is optimal (i.e., produces no more and no less than the recommended ash band); and,
- make sure all gaskets and seals are in good shape so the combustion chamber isn't cooled by air infiltration.

Please add to the list anything within the OP's control.

Mike

Sting wrote:
1) Make sure the zone pump(s) or electromagnetic zone valve(s) are running or active while there is a call for heat in the load and-- AND while the boiler is above condensing temperature.

2) As previously suggested [by others] - be sure the system is circulating - check your supply and return temperatures for at least a 12% delta T - be sure the lines are not air bound!

Kind Regards
Sting

The fire in the pictures on page 1 looks awfully "lazy" to me, but the other KAA-2 guys will have to common on that.

farrell2k wrote: I am more than happy to pay someone to take a look at this for me. Money is not an issue. I have tried calling a few guys in the area and the ones who have got back to me refuse to look at coal.

http://www.anthracitecoalstokers.com/

Try Matt Direnzo. I don't know him personally, but other forum members have given him high marks on getting their systems serviced/tuned.