New Keystoker K-4 Problems

Hi Folks,

This is my first post. Prior to getting the K4 I ran a Heatmor 200 Outdoor Furnace for eight years. It was fantastic. However, all good things come to an end. I've had back surgery and two artificial hips and wood gathering is now out of the question.

We've had the K4 installed in my workshop as it had an existing masonry chimney and plumbed it into the existing system that we'd used for the outdoor furnace.

Now to my problem. I cannot get the K4 to run at a reasonable temperature. Right now it's sitting at 125F. The Honeywell Aquastat is set at Hi=200 and Low=180. The house thermostat is set at 72F.

Other information: It's just below freezing outside. If I use the oil furnace to get up to the 72F temperature the K4 will hold it even though the water temperature is at 125F. The water pump is pumping 5 gpm through the system. The house is very well insulated (3000 sq. ft.). The hot water circulates through the heat exchanger in the plenum of the oil furnace. The house thermostat regulates the temperature by simply turning the oil furnace fan on and off.

I'm concerned that once we start getting temperatures in the - 10F range, we won't be able to stay warm.

See pictures below

Thanks for any help you can provide.
Hank

Go right to the source. Call Keystoker direct and ask for Don. They are there M-F 7-3 Sat 7-12 They are very good at helping their customers. They will walk you right through it over the phone. 570-385 3873

How have you calibrated your baro damper?

How is the feed rate screw adjusted.? How about the combustion air. ? Some units have a cover over the inlet of the blower, most keystokers run about 1/2 open.

Sounds like something is not letting it kick up the feed for more heat. Like the thermostat or aquastat is not telling the stove to feed more.
Might just be idling with the idle timer. Whats your idle timers pins set at?

Is the stoker running nonstop?

The damper is about half open. The baro reading is -.02 as the manual states. The feed screw is set at the suggested point which I believe is 11 turns out. The fire itself is exactly what the manual suggests it should be - about 1 1/2 to two inches of ash and the fire is about two inches deep and full width.

The idle timer pins have the small fan come on every twenty minutes and it runs for 30 seconds.

The installer/dealer called Don's office. The person just told him to set the aquastat at 200 and 180. That's obviously not working.

I've been checking it quite often, perhaps every half hour and the feed and fan are always working. The fire looks great but the water temperature barely climbs.

Yesterday I tried and experiment. I unplugged the water pump and waited until the boiler temperature climbed to 180. At that point I put the pump back on the the boiler temperature slowly dropped back down to below 140.

BTW, it's held the house temperature at 72F since I turned the oil furnace off about 8:30 this morning.

I appreciate the suggestions.
Hank

if it's calling for heat, via the aquastat, the flames should be higher and it should feed continuously to make up the heat. If it's not feeding conintuously on call for heat, sounds like the aquastat is not functioning properly or not hooked up correctly.

If it's calling for heat by the aquatstat and it's feeding continuously, then maybe you just need a little feed adjustment, maybe turn it in 1 turn at a time and let it settle out and see if that helps raise the temp.

Do you have a large loop you are trying to heat? maybe it's really cooling the water down or you need to circulate it slower/fast etc.....cut back the flow with the valve if possible.

There are some rules of thumb which have appeared in various threads. For heat transfer, maximum gpm: 1/2” - 1.5 gpm, 3/4” - 4 gpm, 1” - 8 gpm, 1-1/4” - 14-17 gpm, 1-1/2” - 22-25 gpm, 2” - 45-50 gpm.

One gallon per minute of flow (GPM) will move NO MORE THAN 10,000 BTU's of energy in a fault tolerant manor.

you list above your pumping at 5GPM ???? how do you know

The near boiler piping appears to be too small - what size it is really

do you have valves on the SUPPLY side of your pump/ circulator

how exactly is this appliance hooked in concert with the oil boiler and your load
What EXACTLY is the pump your using - MY GUESS ONLY with limited information is its too big and so is the radiation in the load
What is the load radiation consist of ??? convectors?? Huge radiators??
how many zones ??
did youever do a heat loss calculation to determine if the coal boiler at 80% would carry the load?

I am sorry - my responses are limited -- You Must ask the right question

Hi Sting,

The plumbing on the furnace and the kytec piping are all 1 inch.

The pump is a Grundfos Alpha which gives a constant LED readout on the GPM and Watts currently being used. One can set is a various GPM or put it on auto.

The feed from the K4 goes to a manifold where the hot water is directed to the heat exchanger on the furnace (forced air furnace) and the heat is circulated through the house using the oil furnace fan. The manifold is valved so that some of the hot water can be directed to a side-arm heat exchanger on the hot water heater. This draws very little heat as there are only two of us in the house and as soon as the water in the hot water tank is up to temperature, it takes very little heat to keep it there.

There are four zones: House/hot water heater/small sunroom/shop. The shop valve is turned off as the K4 is located there and the radiated heat now keeps it warm.

The dealer/installer has done the math and the K4 has ample capacity to do the job for this house.

WNY, I'm going to ask the installer to check the aquastat. It could possibly be causing part of the problem.

Thank you to everyone who's trying to help me solve this problem.

Hank

Do you know the BTU size of the heat exchanger in the duct?

your pumping at too hi a rate for the amount of energy the boiler is actually producing in relationship to what the convector is capable to give up

Slow the circulator down as far as possible

then use the valve on the supply side only of the circulator and choke that flow - start about 2/3 open

does the boiler keep up now?

Sorry if my explanations are confusing. When I speak of the furnace, I'm talking about the K4. The heat exchanger which is in the ductwork of the oil furnace is simply a way of converting the hotwater heat from the K4 to our house which was set up originally for forced hot air.

I know that I'm grasping at straws here but could an under-sized expansion tank affect this problem?

Sting, I'll slow the pump down and choke the flow as you suggest. I'll report after I let it run for a day.

Hank

His pump is not a fixed output type pump.
It can be changed to suit most all applications.

I'm no boiler expert but, I have my Kaa-2 settings down to a science. I'd recommend putting the triple aquastat settings at 160* LOW, and 180* HIGH. This will kick start the stoker sooner than a low setting of 180*. Low of 180* does not even make sense to me. MY Kaa-2 has 3 groups of 3 pins at this time. As the weather gets colder, I'll ad another pin to each group, in order to shorten lag time. Shortening the lag time will lessen the overshoots. In the dead of winter, I'll be up to 3 groups of 5 pins. When approaching spring time, I lessen pins. My stoker feed setting is turned all the way in clockwise, then backed out 3-1/2 turns. Sounds like you adjusted your feed from the bottom up. One thing I found with my Kaa-2 is that I'm better off with MORE shorter stoker strokes, and bigger idle fire (adjusted with timer pins, according to weather), than I am with longer stoker strokes, which causes too much fire on the grate, and overshoots. Too much fire on the grates when thermostats are satisfied, triggers high temp aquastat, in order to get rid of excess heat. Too little of fire on the grate when a call for heat, increases lag time. In other words, you need to learn the best settings for coal on the grate during idle time. And that's all you need to know because, when a real call for heat is demanded, the triple aquastat takes over regardless of your settings. The other question I have is; what triggers the circulator pump? Or is it running all the time?

It may be that the OP is being fooled that all the air has been removed from the piping system.

Turn up the ALPHA pump to speed III (3) for an hour or so to try and purge some air.