Hello everyone, very glad I found these forums.
I have just bought a building which has 2 Olsen OMGB-250 gas boilers, with a Tekmar 264 control. The control unit has a lot of settings which are confusing even after reading through the manual. Calling the company that installed it didn't help, they didn't even show up. Anyhow, from what I can see these are the current settings:
Room temp occupied - 72 F
Design temperature - 140 F
Outdoor design temp - 0 F
Terminal unit - 4 (fin-tube convectors)
Mode - 1
I think this might be a problem since the manual states the following:
Mode 1: 4 Single stage boilers and a primary pump.
Mode 2: 2 Single stage boilers with individual boiler pumps and a primary pump.
Mode 3: 2 Lo / Hi boilers and a primary pump.
Mode 4: 1 Three stage boiler with a boiler pump and a primary pump.
The design of my unit is not even listed because I have 2 boilers (no idea how many stages) each with their own small pump, but only the first boiler has a primary pump. The second boiler's individual pump is directly attached to the hot water pipe AFTER the primary pump. Also, I have a separate boiler for DHW which is not connected in any way to this system.
Recently the temperature in one of the apartments was 55 F which is unacceptable. So I went to check the boiler temps and I found that the supply temperature target was 134 F but the current temperature of the water was only 120 F. So I increased the Design temperature to 160 F and the target was changed to 145 F, but even after a warm spell outside and checking the temperatures every day I found that the supply temperature would never rise above 121 F. I also noticed that even though the control unit says boiler 2 was on the whole time, it actually only turns on for a couple of minutes at a time. (I read another thread with the same problem that said this could indicate an air bubble or a failed pump. All pumps are working and I have bled the fin tube convectors in all 47 units and the outcome is still the same.)
Tekmar 264 manual: http://www.tekmarcontrols.com/images...e/264_d_06.pdf
Boiler manual (not very helpful with max temp settings, although does state that the boiler itself also has a control for high temps): http://www.ecrinternational.com/secu...ument/2427.pdf
Any help would be greatly appreciated.
Last edited by MrSabre; 02-02-2013 at 11:12 AM.