Yellow Flame to Tri-Burner Conversion. What Do You Think?

There seems to be a couple different "boiler bypass", the one I describe above is a active circulation boiler bypass. This one needs the 2 valves shown to be able to adjust how much water gets to bypass the boiler.

The other you described is a static boiler bypass, in that it is for when NO circulator runs to do as you said and even out the resting/standing boiler temp. This one may only have one valve.

It might be possible to have both bypass functions in one as long as the 2 valves were installed.

That's interesting, there is more than one type of boiler bypass. I didn't see that come'in. After spending a lot of weekends over the passed two months re-plumbing, I'm not that motivated to do any changes. I think I will work on updating the controls for now.

-Don

Boiler bypass, system bypass, equalizer loop...all depends what you want to do.

Rob,

We got started on the bypass discussion because of the fact that currently as soon as my thermostat calls for heat, the pump and the blower come on. this causes 160 feet of PEX and a heat exchanger full of 80-100 degree water to be dumped into the boiler. At the same time the blower is blowing cold air through the heat exchanger. All this causes the boiler to play BIG time catch-up.

My thinking is, there must be some modern controls that I can replace my 1966 aquastat with that will manage these conditions better. I have a new Tork timer on the way that will hopefully solve idle/full burn issues.

-Don

Shouldn't the blower wait until the water in it is hot enough? I'm no hydronics expert, but isn't that pretty common in modines, etc. (analogous to the fan limit switch in a furnace)?

Also, it probably shouldn't be a surprise if it takes a Tri-burner stoker a while to heat up the thermal mass of a YF boiler and all of the water in the lines.

Mike

Mike,

Agreed, The thermal mass and the little stoker are a problem. After running this setup for a while, I think this will work deeper into the cold season than I first thought. BUT, it will require better managment of the burner, pump and blower. The proof is, I have made this work by running the house zone pump 24/7. I don't wish to do that, and I don't want to plumb in more aquastats, there has to be a better way. I am sure I am not the first one to run into this.

The problem with the blower is that most heating systems with a blower are NOT heated remotely. So, my blower thermo-switch has to be in the ON position for the relay signal from the aquastat to activate it.

There is a simple idea to try! If I can mount the thermo-switch above, and maybe even in contact with the heat exchanger, perhaps that will activate the blower by heat exchanger temp! I will try that this weekend.

-Don

SDon, Another similar method for only starting blower after HX has reached a set point is w/ similar device to what is used in your BoilerMate.

This method will likely req. a relay...and possibly a transformer, though.

StokerDon wrote:There is a simple idea to try! If I can mount the thermo-switch above, and maybe even in contact with the heat exchanger, perhaps that will activate the blower by heat exchanger temp! I will try that this weekend.

Most hot water Modines I have seen have an aquastat mounted right on the unit. The thermostat turns on the circulator, and once the aquastat sees the setpoint temperature the blower kicks on.

I made some BIG improvments on the controls today.

First, now don't laugh to hard, this has got to be the worst Rube Goldburg I have ever done. I found that a thermostatic blower switch that I had laying around fit nicely between the supply and return headers on my heat exchanger.
This fan switch already had a 120V plug and a 120V outlet for a distribution blower. I plugged my blower relay into it.
Electricly, this means that the house thermostat must be calling for heat AND the headers of the heat exchanger must reach a certin temperature to activate the blower.

Next, I insulated the heat exchanger headers and blower switch.

I first covered the headers with foil tape.
Then, insulation and then Gorilla tape to hold it all in place.
I tested this a few times this afternoon and it did work. The settings will likely need tweeking once it gets cold out.

Then, it was out to the garage to say goodby to the rehostat and the S400A timer that have been limiting the Tri-Burner's potential.
Then, I installed this nice Tork percentage timer.
There it is all hooked up and hung on the wall.
So now the rehostat is tunred OFF and the new timer is set for 10% every 8 minutes. The feed rate is set for just about push'in lit coal off the grate on a long heat call. I started running on the timer about 11:00 this morning, no outfires yet, I think it works. I might be able to trim the timer down a little after I get the feel for it.

It should be cold for the next few days, that will be the real test.

-Don

Did an 80 pound fill up this afternoon.

-Don

StokerDon wrote:Did an 80 pound fill up this afternoon.

-Don

Don, how many days of DHW did that 80 lbs. provide?

Have you considered cutting the feed rate back enough to produce a 1-2" ash band on a long run? Otherwise it seems like you'd be dumping burnable coals into the ash pan, defeating at least some of the purpose of all of this.

Mike

lsayre wrote:

StokerDon wrote:Did an 80 pound fill up this afternoon.

-Don

Don, how many days of DHW did that 80 lbs. provide?

Larry,

It was 3 days since the last fill up. That's 26.67 pounds per day. I have been playing around with different feed rates and sometimes running the house zone pump all night, that makes it use more coal. With these new controls in place it will take some time to get it all dialed in. A few weeks ago it was about 18 pounds per day for DHW. You can look through this thread to find out for yourself. I post every fill up, kind of like a log book, except I don't have to be near the boiler, or even at home to look at the archive.

-Don

Pacowy wrote:Have you considered cutting the feed rate back enough to produce a 1-2" ash band on a long run? Otherwise it seems like you'd be dumping burnable coals into the ash pan, defeating at least some of the purpose of all of this.

Mike

Mike,

Well, I guess it's set at about 1/2" of ash, it's avery small grate. In this phase I am trying to get the biggest difference between idle and full burn. maybe I got carried away. I will dial it back if it seems like we are on the rich side.

-Don

So far, so good. The temps were in the low 40's last night and it was very, very windy. When I got up this morning, the house was 68 degrees. I have the T-stat set for about 65.

When there is a heat call it takes about 5 minutes for the blower to turn on. The blower runs for about 5 minutes or so then shuts off to let the boiler catch up again, about 15 minutes. After that the blower runs until the heat call is satisfied.

-Don