Tekmar 297 Steam Boiler Controller - Share Your Settings

sreja

I am a proud new owner of a Tekmar 279 steam boiler controller -- based mainly on advice from this forum.  It is a beauty of a machine and was a pleasure to install.



I thought maybe it would be nice to have a thread where people who have this controller could share their settings, since there are quite a few.



I don't really have any good ones yet since it was just installed today -- hence my curiosity about what you guys set yours to.



Here are some of the available settings:

Minimum On Time

Indoor Design

Outdoor Design

Boiler Design %

Room (OCC)

Room (UnOCC)

CycleLen

Lockout Diff

Setback Hours

WWSD (Occ)

WWSD (UnOcc)

Optimum Start?

Boost?

Limited UnOcc?

sreja

Tekmar 279 Steam Boiler Controller - Share Your Settings

I thought i would share my excel spreadsheet that i print and use for keeping track of settings and observations on the Tekmar 279.



File attached (i hope).

Dave in QCA

Settings at the Louis P Best Mansion Apartments

Here are the settings on my Tekmar 279, installed in September 2008.

Minimum on time - not used because condensate sensor is used

Indoor Design   60F

Outdoor Desing    -20F

Boiler Design %    60%  My boiler and radiation is oversized for the building

Room (OCC)     72F

Room (UnOCC)  Not using setback

CycleLen    AUTO   System decides based on conditions what the cycle lenght will be.

Lockout Diff   Not using. 

Setback Hours   Not using

WWSD (Occ)   55F

WWSD (UnOcc)   Not using, no setback

Optimum Start?     Not using, no setback

Boost?   Not using, no setback

Limited UnOcc?   Not using, no setback

Condensate Temperature     190F  I have it set higher than the default to make sure that steam gets to top of risers in a short cycle.

Randy Baerg

279 settings with some explanation

Here is some explanation and suggestions for settings

on the tekmar 279 steam control. Note: Generally the factory settings are a good

starting point.

Your list of settings:



Minimum On Time -  does not apply if using

a condensate return sensor



Indoor Design – typical standard room air temp = 70°F



Outdoor Design – set this to the coldest outdoor temperature experienced in

your town.  E.g.-10°F.



Boiler Design % - 100% is good, unless your boiler is oversized. Turn down if

you want less than 100% run time on coldest day. E.g. 90%







Room (OCC) – Leave it at 70°F for most applications. If

using an indoor sensor this is like the thermostat setting.

Room (UnOCC) – Set lower than Room Occ to shift Heating

curve lower. E.g. 60°F. Only used with setback.                                





CycleLen – Usually a longer cycle length is better for steam. This allows the

outdoor reset to have more

chance to alter heat output. Automatic is usually best or, if manual, try

starting at 60 minutes.





 Lockout Diff – Keeps boiler off until condensate temp. drops this amount below

the ‘steam established’ setting. It ensures that the condensate gets back to

boiler before refiring.





 Setback Hours – If you want setback set up a schedule

and times. E.g. 24 hour, Occ = 5:30 am, Unocc = 10:30 pm. The control uses the lower (Room Unocc)

Heating curve, and WWSD Unocc.





WWSD (Occ) – Warm Weather Shut Down, disables heating when outdoor is above

this E.g. 70°F.



WWSD (UnOcc) – If setback = On. Warm Weather Shut Down at night. E.g. 55°F.







Optimum Start? – On or Off. Only available for setback with Indoor sensors. If

= On control learns to start early.





Boost? – Only for setback without Indoor sensors. You can set a Max time

control boosts output when coming out of setback.





Limited UnOcc? – Only for setback. Limits on-time calculation to 85% during Unocc.

Energy saving feature.





 Hope this helps.







 

sreja

Tekmar 279 Settings

Great to see some people posting to this thread!



My current settings are:



Room Occ: 67

Room UnOcc: 62

Note that i have 2 indoor sensors installed, one in a semi-heated small room near a window to deliberately try to simulate effect of wind on heat loss in the building.



Optimum start: off

Boost: n/a with condensate sensor

Limited UnOcc: off

Outdoor Design: 10 (default)

Boiler Design: 10 (default)

Indoor Design: 67 (matching room occ sensor)

Cycle Length: 60 (default)



Steam Established: 150 (set at end of 2 pipe steam main as discussed in other threads, not on condensate return which seems useless)

Lockout Differential: 50 (not sure if i should set this  higher)

WWSD Occ: 50 (might set higher havent had much chance to experiment with this since the tekmar has only been installed for a week!)

WWSD UnOcc: 54 (ditto)

Occ Schedule: 5:30am-11:30pm (residential building)

sreja

Tekmar 279 settings

Cycle Length is the one thing that i don't have a great handle on what I should set it to.



And Cycle Length AUTO is intriguing.. wish that the Tekmar people explained in more detail how it decides on cycle length.



For those of you using AUTO cycle length, do you feel like you have a good idea what range of cycle lengths it uses in different cases and how it is calculating it?

sreja

tekmar 279 controller settings

sounds like maybe i have my steam established setting perhaps too low, and my lockout too high -- resulting in it forcing the system cool down too much between cycles.

Dave in QCA

My observations of the AUTO cycle length setting

I have observed that the specified cycle setting will always cause the boiler to fire whether there is a need for heat or not.  For example, if the cycles are set for 1 hour and the system is not in Warm Weather Shutdown, the controller will cause the boiler to fire and establish steam, even if the cycle length required once steam is established is 0%.  In the Auto setting, if the system has overshot the space temperature, the variable cycle length will allow the system delay the start of cycle until space temperature has fallen in line with the set point. 

I have noticed that the Auto setting will usually run a 1 hour cycle on my system.  I think it looks at space temp stability.  I have noted that occaisionally, in very cold weather, the system may overshoot just a bit.  This may cause the next cycle firing time to be relatively short.   Then, as this short fired cycle, say 10% proceeds to time out through its "off time", if the system senses that space temperatures are starting to fall, it will cause the next cycle to begin early.

I have found the Auto setting works best in my application as far as providing a stable and consistent space temperature.

sreja

re:Tekmar 297 Steam Boiler Controller - Share Your Settings

Dave,



That is *super* useful information.



During my brief week with the Tekmar, I have also noticed that on the fixed cycle time (60 mins), it runs the boiler for a small part of each hour even when the indoor sensors are all above their setpoints, which seems like it might be overkill.



Sounds like you are saying that the AUTO setting might be a good fix for that -- and allow it to make better use of the indoor sensors.  Excellent, I'll give it a try. Thanks!

Haviara

My settings

I just installed my Tekmar 279 and wanted to share my settings. This thread was a very good guide to set mine up. I had to adjust my indoor set temperature 1-2 degrees higher as my electrician installed the indoor sensors closer to the ceiling and out of the way of tampering hands..

24 unit building, 4 floors, 1 pipe system

Minimum On Time- I used condensate sensor on the furthest return at the end of the main.

Indoor Design- 70 default

Outdoor Design - 10

Boiler Design % - 80- Still playing with this number but boiler is def oversized for the building. When I set to 100% the system overshot by 15 degrees

Room (OCC) 70

Room (UnOCC) 65

CycleLen- Auto- Still playing with this setting

Lockout Diff- Left it at 30 but may be better at 50 for my system.

Condensate temp at the end of cycle is about 190.

Setback Hours. 10:30 PM to 6 AM

WWSD (Occ)- 55 (matching NYC rules)

WWSD (UnOcc) - 35(matching NYC rules)



Optimum Start?- Yes, I want the system to learn and get my tempurature to 70 by 6AM

Boost? NO

Limited UnOcc? NO