What Exactly is The HLF Setting On the Coal-trol Controlling?

What exactly is the HLF setting on the coal-trol controlling? Is it the lag to lower the feed rate once the T-stat sees the set temp? In my house my T-stat is kind of far from the stove heat so it takes a while to get to temp and once it is at temp the feed rate drops but then it will become quite a bit cooler in the house before the stove responds. It just seems like a vicious cycle up and down and I think it would work better if the feed rate did not drop as fast or if the feed rate had a longer dwell at the higher feed once the T-stat saw the set temp.

Gambler,

Repost this question on the Coal-trol topic page and you will get a quick responce from them.

I think that HLF was designed to address the very problem you are having. They told me not to use it.

BK

Gambler,

Repost this question on the Coal-trol topic page and you will get a quick responce from them.

uummmmm I thought that is where I posted it. I know that I am getting old and forgetful but you made me look twice to see where I posted this at.

Sorry, I didn't read the heading.

BK

Just started to set mine up and wondered the same thing. I will set it for 1 to see what it does. I thought it was the Heat Loss Factor of your house/insulation, etc....how fast does your house cool down? You may have to to raise the value, so it "anticipates" the temp drop and starts feeding it earlier to maintain the temps.

Gambler and WNY,

HLF does indeed mean Heat Loss Factor. The higher the setting, the more aggressive the increase in feed rate will be at a setpoint change. There are a couple of issues with using this setting:

1) It can result in an "unstable" control situation. It should only be used when there is an overly long delay in getting to temperature on a positive setpoint change. Make sure you've eliminated other possible problems first, though. For instance make sure you have good air circulation and that the thermostat is installed on an interior wall. Changes to this setting should be made slowly. Increase it one step at a time and try the setting out for a day or two to see if it is helping or hurting.

2) If you bought a thermostat manufactured last year there is a possibility that you have one that has a bug in the HLF implementation that can result in erratic behavior if HLF is set to anything but 0. If you think you need to use this setting check to make sure the version display (at the end of the TEST cycle) says "V2 ###" with ### being 020 or higher.

If you believe you need to try this setting we also encourage you to call us (315-299-3589) so we can discuss your situation in detail, both so we can provide some guidance and so we can find out more details about your installation. We're constantly working on the thermostat software, this information can help us make future versions better.

Thanks pvolcko, My T-stat is on an interior wall but I am going to try to move the air around the house better to see if that helps first. If I still have a problem with the temp dropping faster than the T-stat can keep up I will give you a call. Other than this lag issue that I have the T-stat is the cats azz in controlling the stove.

Well I did a small experiment, I am using a fan to remove heat from the room the stove is in and the stove was at idle and the ouside temp is 51* and the house temp was 69*. I bumped the T-stat up to 71* and that was 2 hrs ago and the house temp now reads 70* and my feed rate is at 30. I am off of work tomorrow so I guess I will call pvolcko to see if he can help me out.

Gambler, when you call you'll be talking to Neil. I'll send him email tonight to explain a bit of the situation to give him a heads up.

A couple of comments/questions though:

1) Was it substantially warmer in the room where the stove is compared to the room where the thermostat is? If so, this would indicate an air circulation problem. Depending on floor plan it can be very difficult to get the air to move around, even with the use of a fan. Instead of trying to blow hot air out of the stove room, try "sucking" cold air into the stove room, especially if you're using a floor flan.

2) In the experiment you mention, where it ended up at 70 degrees with a setpoint of 71. What was the setpoint change you made? You said before the experiment things were idle with a temperature reading of 69 degrees. What was the setpoint at during this time? During the two hour experiment had the temp at the thermostat gone over the setpoint of 71 or was it still "lagging" and the feedrate was still climbing very slowly?

3) What brand/model of stove are you using? What is the max BTU output of the stove? What are your MIN and MAX setting in the SETUP menu? Sometimes in the fall and spring when the outdoor temperature is not that low it can help to set the MAX lower than usual. This has the effect of making each point of feedrate (FR) actually translate into less stoker on time. This should help minimize the chances of "overshooting" in "low load" situations, such as when it is 50 degrees outside, especially when the heat from the stove is not efficiently reaching the thermostat.

We will do everything we can to get you up and running to your satisfaction, but please bear with us as we work with you to try and figure this out.

Paul,

I did buy mine beginning of this year and it is mounted on an interior wall about 10 feet from the heat duct.

I did see the version number but didn't write it down. I will check it once I get it up and running this weekend to see if the HLF has a problem. If not, I will leave it at (0).

WNY, of course you are free to experiment. However, it is suggested that you only change the HLF setting if you are having a problem with it taking "too long" to achieve a setpoint change. "Too long" is a hard value to quantify as it is dependent on stove BTU output, size of the house, quality of air circulation, insulation factor, etc. In order for our control to remain stable at the majority of installations we had to be very conservative with how aggressively it makes feedrate changes. This HLF setting allows for the user to dial in a more aggressive feedrate "bump" when a setpoint change is made, in theory allowing the new setpoint to be achieved more quickly. But if it is set too high it will result in either large overshoots (but not instability, which you may be comfortable with) or instability (where the control takes much longer to stabilize at the setpoint temperature).

Okay, no problem..... I will start at (0) then. We do have new windows, insulation, etc...so I will see how it keeps up hopefully this weekend. Thanks!!

I have an LL Pocono, new this year, and am dealing with the same sort of thing

I had the thermostat set for 68 over night, and 71 at 6:30 AM

When I got up at 9, the temp was 69, feed rate 34%. Then a little later, it jumped to 99% and the heat began to rise.

Later, at 5:45 I set the temp from 71 to 72, nothing happened until 9 PM when the FR began to rise, at the temp hit 74 at 10:30

Strange thing is, 10 pm is the time the temp is supposed to drop to 68.
I look, just before starting this post, and the FR has dropped to zero.

I would think the logic would have a rapid change mode for when auto change point are reached (and manual changes are made), and then gradually level at the new set point.

Also when reducing the requested temperature, it seem to continue the FR for a very long time before reducing the FR.

I will try HLF of 1 and see what happens in the morning.

Well insulated house, double pane, and am only heating about 1200 sq ft of the living space. The stove is in the basement, the heat being distributed by my oil furnaces blower. The basement is cooler than the living area.
I do not believe the distribution system is any part of the problem, based on the low feed rate observed 2 hours after the thermostat requested a 3 degree increase. Also, If I leave the thermostat set at 70, night and day, the temperature remain consistently at 70. It is only when a manual or automatic temperature change is requested that there is a long delay before the FR rate noticeably changes.

EDIT: another factor may be that my Max was set to low. It was still at 40 last night. Today while the thermostat was recording 99% FR, I adjusted the Max setting to 60. There is the possibility that the thermostat thought that more heat should have been being produced based on it expecting a larger fire at lower feed rates, resulting in a slow warm up.
Increasing the Max Setting resulted in an increase of over 125 degrees as read on a magnetic coil thermometer on the upper front of the stove.

HLF 1 was not the answer.

Version 2 017

Overnight temp was set to 68
Day time temp of 72, change at 7:30

At 10 am the temp is 74.
The feed rate 93% at 10 am
83% a few minutes later.
Now it is 73%

Sorry I didn't get readings between 8:30 and 10:00, I slept later than expected

Just talked with wife and other stuff before hitting Submit. Checked FR and it was 74%, it doesn't seem to want to admit it is 2 degrees over temp in here.

EDIT: to try and straighten out Daylight and Standard time conflicts.
10:45 temp 75, FR 68%

EditEdit
11:30 temp 76, FR 34%
12:00 temp 76, FR 18%
1:00 temp 75, FR 0%
2:15 temp 74, FR 0%, outside temp has risen to 49 here in the finger lakes of new york

V2 017 has the HLF bug. Anything but HLF 0 can result in very eratic behavior (though the results you posted in this mode appear to be normal). This HLF bug exists on all thermostats prior to build V2 020.

With the temps not being that cold outside today and your having a well insulated home, it will take a very long time to bleed off the overshoot heat. In this case it looked like roughly 1 degree per hour. The rate of the FR drop is also normal for a 2-4 degree overshoot condition. For a 4 degree positive setpoint change, a 99 or near 99 FR after 2-2.5 hours is also normal.

I'll comment further in PM. Once we get to a resolution I'll post an update for the benefit of everyone. Getting to the resolution may take a while though, better to handle offline.