Visual Chart of Self Adjusting Cycles

PMJ

For those interested, attached are two charts of a recovery this morning. Apparently my wife stayed up most of the night preparing for the holiday (I gave up many years back trying to stop this). She turned the boiler off and opened some windows. The house was down in the mid 50's so there was more than 10 degrees to recover.

Anyway, I doubt anyone has seen this charting approach but it shows recorded time to steam at the remote sensor(TTS in red), total burn time(blue), time to cool from end of burn at the remote sensor(TTC green) and total wait after the end of the last burn(black). It takes a little study but give it a shot. Total wait times between burns 16-20 minutes so right around 2 burns an hour.

It took four hours or so to recover all that (I spread it out on purpose). The call was continuous the whole time and there were 9 burns. The first burn took 20 minutes to get steam to the remote sensor after being off 7 hours or so.

Notice though that with each cycle the TTS is falling slightly but the total burn time is increasing. That is because the control fires the burner until both the remote sensor is satisfied and all the vacuum is gone. With each cycle the vacuum deepens a little producing a longer total burn. The time to reach a cool sensor after each firing then increases as more steam is pushed out each time into the same conditions.

I have found this approach quite sensitive to outside conditions. When it is colder obviously steam condenses faster. The burns get closer together and run a little longer as needed. But the result is always quite even as shown. It can't not be even. Had my boiler been allowed to run straight/ with pressure stops to recover this it would have been most unpleasant. One switch on the front of the control takes it back to straight burning original if necessary.

The charts are the same, just on different time scales.

hot_rod

colorful info

ChrisJ

So...

The few times I tried this method with the ecosteam the house continued to get colder and colder until it started to catch up and then it ended with a 5 degree overshoot.

PMJ

ChrisJ said:

So...

The few times I tried this method with the ecosteam the house continued to get colder and colder until it started to catch up and then it ended with a 5 degree overshoot.

One of the main factors in this method is vacuum which as you can see changes the length of the burns. I'm not sure how you try the method without that.

There are also two fixed timers you can't see. Burns run a fixed 210 seconds after both a make at the remote sensor and all vacuum is gone. In mild weather there are many fewer firings and vacuum rarely extends the burns. In cold weather every burn is extended by vacuum. There is also a 180 second wait beyond the remote sensor opening again before the next burn can start. I don't ever change these. But they do establish a minimum fill level that I know from experience in a continuous call will keep up on design day. So at all other times it system runs clearly ahead of the demand, but nothing like the overshooting that would happen with this size boiler and the standard control.

ChrisJ

PMJ said:

So...

The few times I tried this method with the ecosteam the house continued to get colder and colder until it started to catch up and then it ended with a 5 degree overshoot.

One of the main factors in this method is vacuum which as you can see changes the length of the burns. I'm not sure how you try the method without that. There are also two fixed timers you can't see. Burns run a fixed 210 seconds after both a make at the remote sensor and all vacuum is gone. In mild weather there are many fewer firings and vacuum rarely extends the burns. In cold weather every burn is extended by vacuum. There is also a 180 second wait beyond the remote sensor opening again before the next burn can start. I don't ever change these. But they do establish a minimum fill level that I know from experience in a continuous call will keep up on design day. So at all other times it system runs clearly ahead of the demand, but nothing like the overshooting that would happen with this size boiler and the standard control.

How exactly is the burn extended by vacuum?

PMJ

ChrisJ said:

PMJ said:

ChrisJ said:

So...

The few times I tried this method with the ecosteam the house continued to get colder and colder until it started to catch up and then it ended with a 5 degree overshoot.

One of the main factors in this method is vacuum which as you can see changes the length of the burns. I'm not sure how you try the method without that.

There are also two fixed timers you can't see. Burns run a fixed 210 seconds after both a make at the remote sensor and all vacuum is gone. In mild weather there are many fewer firings and vacuum rarely extends the burns. In cold weather every burn is extended by vacuum. There is also a 180 second wait beyond the remote sensor opening again before the next burn can start. I don't ever change these. But they do establish a minimum fill level that I know from experience in a continuous call will keep up on design day. So at all other times it system runs clearly ahead of the demand, but nothing like the overshooting that would happen with this size boiler and the standard control.

How exactly is the burn extended by vacuum?

Look at the chart and read what I wrote again.

After the first warmup burn of 20 minutes the next time to steam is 4 minutes and total burn 8 minutes. On each burn after that time to steam gets slightly shorter but notice total burn time gets longer and longer from 8 to 10 minutes. This difference is controlled by how much vacuum is in the system. When each burn starts the system is in the deepest part of the vacuum cycle. The deeper the vacuum, the more vacuum will still be left in the system when steam gets to the sensor. I don't initiate the end of burn timer until all the vacuum is gone (there is a sensor for that too). So more vacuum results in longer burns. 10 minutes instead of 8. It isn't a nothing difference. The colder it is outside the faster steam is condensing and it takes less time for the same level of vacuum to be created, so vacuum has an increasing effect on burn time the colder it gets.

I attach the system pressure chart for the same time period so you can see visually the vacuum deepening with each burn. Each cycle with deeper vacuum in between produces the longer burn time on the following cycle.

reggi

ChrisJ said:

PMJ said:

So...

The few times I tried this method with the ecosteam the house continued to get colder and colder until it started to catch up and then it ended with a 5 degree overshoot.

One of the main factors in this method is vacuum which as you can see changes the length of the burns. I'm not sure how you try the method without that. There are also two fixed timers you can't see. Burns run a fixed 210 seconds after both a make at the remote sensor and all vacuum is gone. In mild weather there are many fewer firings and vacuum rarely extends the burns. In cold weather every burn is extended by vacuum. There is also a 180 second wait beyond the remote sensor opening again before the next burn can start. I don't ever change these. But they do establish a minimum fill level that I know from experience in a continuous call will keep up on design day. So at all other times it system runs clearly ahead of the demand, but nothing like the overshooting that would happen with this size boiler and the standard control.

How exactly is the burn extended by vacuum?

Steam isn't as hot 🥵 below atmosphere pressure... But hotter than hot water 😂

ChrisJ

reggi said:

ChrisJ said:

PMJ said:

So...

The few times I tried this method with the ecosteam the house continued to get colder and colder until it started to catch up and then it ended with a 5 degree overshoot.

One of the main factors in this method is vacuum which as you can see changes the length of the burns. I'm not sure how you try the method without that. There are also two fixed timers you can't see. Burns run a fixed 210 seconds after both a make at the remote sensor and all vacuum is gone. In mild weather there are many fewer firings and vacuum rarely extends the burns. In cold weather every burn is extended by vacuum. There is also a 180 second wait beyond the remote sensor opening again before the next burn can start. I don't ever change these. But they do establish a minimum fill level that I know from experience in a continuous call will keep up on design day. So at all other times it system runs clearly ahead of the demand, but nothing like the overshooting that would happen with this size boiler and the standard control.

How exactly is the burn extended by vacuum?

Steam isn't as hot 🥵 below atmosphere pressure... But hotter than hot water 😂

Depends on the vacuum.
I make water boil at 60f-70f often enough.

reggi

ChrisJ said:

reggi said:

ChrisJ said:

PMJ said:

So...

The few times I tried this method with the ecosteam the house continued to get colder and colder until it started to catch up and then it ended with a 5 degree overshoot.

One of the main factors in this method is vacuum which as you can see changes the length of the burns. I'm not sure how you try the method without that. There are also two fixed timers you can't see. Burns run a fixed 210 seconds after both a make at the remote sensor and all vacuum is gone. In mild weather there are many fewer firings and vacuum rarely extends the burns. In cold weather every burn is extended by vacuum. There is also a 180 second wait beyond the remote sensor opening again before the next burn can start. I don't ever change these. But they do establish a minimum fill level that I know from experience in a continuous call will keep up on design day. So at all other times it system runs clearly ahead of the demand, but nothing like the overshooting that would happen with this size boiler and the standard control.

How exactly is the burn extended by vacuum?

Steam isn't as hot 🥵 below atmosphere pressure... But hotter than hot water 😂

Depends on the vacuum.
I make water boil at 60f-70f often enough.

Not in your boiler..... without some help.. and when did you add that ?  You didn't do that on the installation originally a decade or so ago. ..did you?