Tekmar 519- Problem?

Cyclist77

I currently have the above thermostat set to sense floor temperature in order to operate the circulator. But I recently been seeing it call for heat even though the floor temp is fine. For example. The floor temp is set for 83F but the floor temp actual is 87F and it triggers the circulator.

Am I missing something?

Thanks!

EdTheHeaterMan

Is this a new problem with a control that has been operating properly for some time?

Is this a new install that has had problem since the Tekmar 519 was commissioned?

EdTheHeaterMan

Second query? Is the Tekmar 519 configured for floor sensor only, or is it set up for air temperature control with a floor sensor (air + slab mode)?

If it is operating in air temperature mode with a floor sensor connected, the room air sensor is the primary control. In that case, the floor temperature setting is acting as a minimum floor temperature.

Operation would be as follows:

• If the room temperature is satisfied (at or above setpoint), the circulator will not run, provided the floor temperature is above the minimum floor setting.
• If the room temperature drops below setpoint, the circulator will run to satisfy the room temperature.
• The minimum floor setting only maintains floor warmth when there is no active call for heat from the room sensor.

If the control is configured for floor temperature only and the air temperature function is disabled, then the floor sensor alone controls the circulator. The circulator will operate strictly based on floor temperature relative to the floor setpoint.

If a maximum floor limit is enabled, that changes the logic: the circulator will shut down if the floor reaches the maximum limit, even if the room temperature is still below setpoint.

So a floor temperature setting of 83° with a room temperature call for heat that is not satisfied will operate the circulator until the room air temperature is satisfied. This could cause a warmer floor temperature like 87°. You may also want to set the Maximum floor temperature if you do not want the floor temperature to rise above a set temperature.

Cyclist77

Ed,

This "seems" to be recent as I have noticed it in the last few weeks.

Here is the back story.

This is a recent Weil-McClain CGA3 install as of November. I have the Tekmar installed in the basement as I am only monitoing floor temp .I have just run new wiring up to the first floor to relocate the Tekmar.

I was just downstairs finishing pulling the wire and I noticed that the floor temp(actual) was 87f and the switching relay kicked it to turn the circulator on .But my setpoint is 84f.

EdTheHeaterMan

This is a recent Weil-McClain CGA3 install as of November. I have the Tekmar installed in the basement as I am only monitoing floor temp .I have just run new wiring up to the first floor to relocate the Tekmar.

November sounds like a recent install to me.

This is a recent Weil-McClain CGA3 install as of November. I have the Tekmar installed in the basement as I am only monitoing floor temp .I have just run new wiring up to the first floor to relocate the Tekmar.

Is it still in the basement?

This is a recent Weil-McClain CGA3 install as of November. I have the Tekmar installed in the basement as I am only monitoing floor temp .I have just run new wiring up to the first floor to relocate the Tekmar.

Is this new wire connected to anything yet?

I am trying to understand all the information provided and ignore the information that is not relevant like running a wire that has not been connected to anything yet.

Cyclist77

Sorry for information overload!

I really started noticing this "problem " because I was right there at the moment the circulator started. I look at the Tekmar and saw the floor temp of 87f and confirmed that the setpoint was 83f.

Hope I cleared the air!

EdTheHeaterMan

More info request:

is the floor sensor in the basement floor?

Is the Tekmar 519 setup to measure floor temp sensor only?

Is the green box set to FLOR

Is the Red Box set to OFF

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/comment/1888558#Comment_1888558

Please answer these queries:

Where is the floor sensor? Basement or other room upstairs?

Where is the Tekmar 519? Basement or other room upstairs?

What is the Tekmer settings for Auxiliary sensor? NONE or FLOR?

What is the Tekmar room sensor setting? ON or OFF?

I'll be back after lunch

Cyclist77

Floor sensor is located on the 1st floor.

Tekmar 519 currently located in the basement.

Auxiliary sensor-Floor

Room Sensor -Off

EdTheHeaterMan

Thanks for the reply. I have a full picture I think. You are correct in your thinking that the circulator should not be operating with the parameters you have mentioned.

• Floor 87°
• Floor sensor is located on the 1st floor.
• Tekmar 519 currently located in the basement.

Settings as follows 

• Floor Temp 83°
• Auxiliary sensor-Floor
• Room Sensor -Off

What is the Floor Maximum temperature set to? 

Also what is the circulator connected to? a zone relay? a single zone switching relay? The boiler control? Sometning else?

Cyclist77

Floor Max set to 87f

Circulator connected to a Taco Switching?

Just had a thought. A while ago I thought I was having a problem with one of the switch relay modules. It was this zone. It "seemed" to start working ok so I didn't change it. Maybe this is the culprit?

hot_rod

The 519 should call on the zone pump or zone valve. Then the pump relay control turns on the boiler.

You will get some overshoot with a slab when it shuts off. It is a bit of a flywheel.

I usually use that stat as both air and slab. Set the temperature to what you want the room, 70°?, limit the floor temperature to maybe 83 or so.

If you use slab only and set to 87 the room will probably over-heat

EdTheHeaterMan

I have a feeling that the Slab Sensor only setting may be working off of the Floor Max setting and not the floor temperature setting. It is a little cryptic in the manual but afteer you understand how the folks at Tekmar write their manuals, you ca nusually fond the clue to how the item works. It may be hidden in the text somewhere if you take the time to read each section about 6 times.

SET FLOOR

Set the floor minimum temperature. Available when an auxiliary floor sensor is connected and the built-in room sensor is on.

This tells me that the  SET FLOOR does not do anything when the ROOM SENSOR is set to OFF.  See how that information is hidden in the wording of this one section?  It does not specifically say that anywhere, but it is in there by way of this one sentence.  That being the case, the FLOOR MAX is what the Tekmar 519 is looking at to operate the system.  So moving the 519 to the actual room it is controlling and setting the control to ROOM SENSOR to ON should solve your problem. 

That way you can set the minimum floor temperature to something lower like SET FLOOR. to 72° and let the room temperature dictate when the circulator pump will operate.

Cyclist77

Thanks Ed!

I will work on it some more!

hot_rod

my memory of that stat, at least the earlier versions , which were labeled under various names, like Uponor. you could choose either a min or max with the room sensor enabled.

So in the summer, with AC on you could still idle a warm bathroom tile floor for example

The max setting was helpful with some flooring materials, or carpet pad that had temperature limits

What Im not sure of is if the stat is set to 72 and floor at 83, which has priority? Will it overshoot the floor setting to get the room to 72?

Or will It ignore air temperature when the floor is set to 83?

EdTheHeaterMan

According to what I read, the minimum temperature setting may cause overheating in the room. There is a caution in the manual about that. On a small zone like a bathroom I don't believe that would be a problem. I believe that is the purpose of that feature, like @hot_rod indicated. On a complete floor of several rooms, I would avoid having a minimum temperature that is in the 80°s. That's just asking for overheating

hot_rod

I don’t think experimenting with various settings will harm the control. Keep trying different temperatures and variations until you get what you want m.

If it flywheels 4 degrees over, and stops, try lowering the settings 4 degrees?

hot_rod

tekmar has always had excellent essay explaining the control logics

This one talks about PWM and drills down on the various operating conditions if the stats with air and slab settings

https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/35982-source/638821557970000000/e0006-06