I Over Sized My Keystoker

I was asking a representative from Thermco who stopped by the office the other day about Triangle Tube hot water heaters. We chatted for a few minutes and he said to email him so he would be reminded to check the warehouse and see what they have in stock. He got back to me this week and said they were all out of the SMART 40's, but they have the SMART 50's in stock. I think I'm going to wait around for a 40 depending on the wait. He said he would tell me in a few days when they expect some to be in.

In the meantime he asked if there was anything wrong with my oil boiler. I told him about the Keystoker and like most people he thought that it was really cool to be using coal. I then jokingly asked if they had any oil boilers laying around the warehouse that they wanted to move. He asked me the size of my current one and I told him it was 144MBH, but I would check again to get the age and model number.

This morning I go into the room and squeeze around the coal flue and strain my neck and tweak my back to read the label. Turns out it's 114MBH!

This tells me that not only is the K6 over sized for my house, but there is plenty of room on it for the hot tub and any radiant floor I might install. It also shows me that my current installation with the oil boiler in series and only one pump is the reason that I cannot keep my house up to temp on cold days. The oil boiler never had a problem keeping the house warm enough and its 30MBH smaller!

If you KA6 is supposedly oversized, why won't it keep up? Then you should have to push the boiler as hard to keep up.

But then you state you have extra capacity for radiant floors or hot tub?

That's something that I havent figured out 100%. I'm thinking its because the oil boiler in series on the return to the K6 and I have one pump pulling thru the oil boiler and then pushing into the coal. The oil boiler being where it is in the loop makes the return water cooler than it should be. I'm really stumped as to why the K6 can't make my house a hot box on the coldest day.

one - if your satisfied that the coal your burning is burning well

two - if your boiler is sized correctly - as you point out over sized for the load your giving it

--- and the only way to tell is if you do you own heat loss calculation using something like this software.
http://www.slantfin.com/ it is great but broke right now The tech at Slantfin said they were having problems with it and they are doing some modification.

Then if your still cold --- Its NOT the boiler -- the problem is in the pipe - circulation method - or the load radiation is wrong

But if the house was always warm with a 114 MBH boiler, why would it not be as warm with a 144 MBH?

My guess would be the circulation.

Hollyfeld wrote:But if the house was always warm with a 114 MBH boiler, why would it not be as warm with a 144 MBH?

My guess would be the circulation.

I would agree. Is the boiler staying within its temp setpoints? If so, you need flow! That thing should be able to cook everything in the house.

you mean as far as it staying within 160-180?

you betcha!

It's never fallen below the Lo set temp.

Can you post some photos of your system? Or a good sketch? It sure smells like fish, ahhhh, I mean something is fishy.

Sounds more like a flow problem to me too. The pumps that come on some boilers are pretty skimpy. Two boilers in series may have created enough head to reduce flow enough to create the heating problem. I doubt the oil boiler has enough heat loss to put any load on the coal boiler.

Freddy wrote:Can you post some photos of your system? Or a good sketch? It sure smells like fish, ahhhh, I mean something is fishy.

I wish I could take some decent photos. The room its in doesnt give me enough distance to allow for a worthwhile photo. Also, the 8" flue from the K6 blocks the view of the oil boiler completely. I'll do redo the sketch I posted a month or two ago and be back on tomorrow.

I can get the pressure drop for the oil boiler and could calculate all the piping, but when I called Keystoker to get the drop through the K6 the man on the phone had no idea what I was talking about. If I had that information, then I could determine if the pump is the problem.

I may have missed it, but what circs are you using? How old are they? Any Zone valves?
What size piping when you go to series with the oil unit.
Did you ever gave a problem before the K6? That boiler should EASILY do what you are asking of it.
Just for kicks, about how much coal do you use daily. (not including this warm spell).
A K2 should do what you are asking, all of us are missing something somewhere.
It seems odd since everything worked with a 114K boiler.

(1) circ - Taco 007 Not sure of the age. It's black and I know the new ones are green. The zone valves are probably as old as the oil system, but the heads were replaced just last year

pipe size - 1"

This is my first winter with the K6 so Im still learning the ropes. The only problem is not keeping my house up to temp when its very cold out.

When the temps were below freezing, I would go thru about 55lbs a day and when they were in the single digits it was close to 100 lbs a day

Hollyfeld wrote:(1) circ - Taco 007

pipe size - 1"

Ding Ding
Ding Ding

I think we have found the/an issue

Hollyfeld wrote: This morning I go into the room and squeeze around the coal flue and strain my neck and tweak my back to read the label. Turns out it's 114MBH!

This tells me that not only is the K6 over sized for my house, but there is plenty of room on it for the hot tub and any radiant floor I might install. It also shows me that my current installation with the oil boiler in series and only one pump is the reason that I cannot keep my house up to temp on cold days. The oil boiler never had a problem keeping the house warm enough and its 30MBH smaller!

Let's see-
114 MBH - 30 MBH = 84 MBH INPUT OR 67.2 MBH OUTPUT on oil boiler. (very small oil boiler) This would equate to about 6.7 gpm on a standard system design of 20 deg. F. water temp. differential. 6.7 gpm is nearing the maximum for a 1" copper pipe at 3.3 feet of friction loss per 100 equivelant feet of pipe. Pressure loss is a square function and skyrockets as flow increases.

Factories to not rate pressure loss through boilers. The loss through the boiler is usually very little. The sudden outlet and inlet of the flows in and out of the boiler have pressure loss though. Additional piping between the boilers may have been just enough extra pipe to lower flow to create heating problem.

The 007 is a good pump but is not a "high head" pump. It has the capability of about 8.5 feet of head at 6.7 gpm. It takes 1 foot of head just to overcome a flow control valve.

Before I recommend increasing the pipe size, did you install a bypass on the keystoker like the manufacturer recommended? Could water be bypassing the boiler and not picking up heat?

Sting wrote:

Hollyfeld wrote:(1) circ - Taco 007

pipe size - 1"

Ding Ding
Ding Ding

I think we have found the/an issue

All of the piping is 1". The old piping on the oil boiler is and the new piping on the coal is too

IRT to Steamup

Yes I have the bypass loop installed and it is valved off at the moment. Here is a basic diagram of the system in the room.