Burnham Alpine ALP080 with Tekmar 403 slow recovery

trent

My control unit is showing boiler target at 160, boiler supply at 120. The boiler goes through the ignition sequence, fires up and runs at 100% until the supply water gets to 145 then shuts off. Or it just goes through the ignition sequence and directly to post purge. Also, it is not running enough to keep the domestic hot water to temp (130). The boiler seems to be disregarding the Tekmar controller.

trent

Outdoor design 0 to 20 (makes no difference). mix design 180. mix type var. boiler type 4-20. Boil design 180-190 (no difference). boil min 0 or 140 (makes no difference). Boil motor 30 sec. min mod 0. mod delay 0:10. flushing off.

CMadatMe

Make sure you're wired correctly. Doesn't sound like you are. Page 7.

http://tekmarcontrols.com/images/_literature/a0002_m_07.pdf

Tekmar needs to be wired to the Alpines "Remote Firing Rate" on the terminal strip as shown on page 71.

https://file.ac/NJoafl8LTOE/Alpine I&O 80 MBH through 285 MBH 2015.pdf

trent

Thanks, Chris. The system seems to be set up like pg 14. I will verify the wiring .http://tekmarcontrols.com/images/_literature/a0002_m_07.pdf

trent

Wiring looks good. I am going to check to see if the main circulating pump is backward. The

CMadatMe

Is the boiler set up to allow the Tekmar control to be the brain so to speak?

wogpa67

How long has the boiler been in operation?
Lp or NG?

trent

The central heat mod source is set to remote 4-20ma but the central heat setpoint source is set at local. If I set the mod source to local, I can then set the central heat set point source to 4-20ma. I cannot get both parameters at 4-20ma. This may be something.

trent

The boiler has been in operation since 2012 and is NG. The installer is out of business but it has always been slow recovering.

CMadatMe

trent said:

The central heat mod source is set to remote 4-20ma but the central heat setpoint source is set at local. Not sure why, but I can't get it to toggle to 4-20. I think you have found the problem!!

I didn't find it. You did. Just gave you a little road map. You may need an installer password to change that. Suggest you re-read the manual from a control standpoint.

trent

i have the password. I need to figure out if this is an either/or setting. It seems to me that both settings should be 4-20ma. (I edited my previous post right before you responded, sorry).

CMadatMe

It's going to be one or the other - You need to make sure that Boiler Min is off on the Tekmar - You also need to make sure the right Minimum Modulation percentage and Modulation delay is correct. They are more then likely not correct. Page 26 for the math. You're going to need to call Burnham to get the right 4-20mA current the boiler operates at. It's not in the installation manual.

http://tekmarcontrols.com/images/_literature/403_d_07.pdf

trent

OK. That makes sense. I have a service bulletin SB 064 from Tekmar that shows the min mod% as 0 and the delay as 10 seconds. Also, it shows that the boiler control setting should be 4-20 on the Central Heating Modulation source. So, it seems that the boiler control determines the setpoints? I reviewed the adjusting parameters on the boiler control and changed the central heat diff above from 2 to 10 and the minimum boiler temp to 140 from 130. This seems to really help! I have convection baseboard with fins and I think the water was too cool to operate effectively and the water capacity of the system is fairly small. The water would heat up rapidly then the boiler would kick off maybe because it was heating up too quickly. The stat was demanding heat for long periods causing the modulation to drive at 100%. This was causing extreme cycling.
Currently it is humming along nicely. 30 degrees out and modulating between 2% and 50%. Not ready to claim victory, but we are on the right track. I had been assuming that the Tekmar was running everything, but that does not seem to be the case.

trent

Crap. Back in the same boat this am. 9 deg outside and central heat struggling to recover. Short cycling from 125 deg supply temp running up to 145. Tekmar boiler target 190. House set at 70 for night.

CMadatMe

Telling you, BOILER MIN OFF - Boiler Min is used only in conjunction with a Cast Iron boiler to prevent thermal shock, flue condensing. Boiler Min - OFF. This is a modulating condensing boiler and you can't be at 0 for a minimum modulation rate %. If 80,000 Btu/hr is 100%- 16,000 Btu/hr is 20% not 0. Tekmar installation manual specifically says that you need to call the boiler mfg to get the proper current for 4-20.

trent

Boiler min IS off on the Tekmar. Boil motor 30 sec. min mod 0. mod delay 0:10. flushing off. tekmarcontrols.com/images/_literature/sb0064_02.pdf

trent

OK. I will check in to the min mod.

CMadatMe

Trent you have to get off of the Tekmar Manual as to the proper settings. The manual clearly states that you need to contact the boiler mfg for the right current for 4-20. Tekmar doesn't provide any of that.

trent

I emailed them. Not sure they will talk to a HO. Something has changed about this system, though. It usually recovers more quickly than this. Operates perfectly once it gets to temp.

trent

Tekmar boiler temp probe was not tracking with the actual boiler temp close enough. It was loose and I also remounted it closer to the boiler. Tekmar support was awesome.

trent

Main cause was high temp limit switch.