WM series 2 Ultra 155 b-25 error code

stephen11962

Ultra 155, TekMar controls, 8 years in service, b 25 error code, outlet temp rise too fast:
Boiler pump, Taco 0014-F1, has 125v at junction box but I cannot tell if water is circulating. Everything else seems OK. Could the boiler pump cartridge be bad?

njtommy

Yes if pump is not running you will get that fault. I would make sure the pump is running first.

stephen11962

I am at a loss about determining if the pump is running. I did slowly close down one of the ball valves isolating the pump and heard what seems to be a restriction of flow of the water.

The boiler sends out (seeming) protests of expansion noises when firing, starting about a month ago. This noise was the thing that got me paying attention to boiler and once while trying to locate the exact source of the noise I saw the error code, which I have now seen seen several times. I followed the trouble shooting steps in the manual, including air in the system, etc.

So, now I seem to have determined that some water is circulating, but enough?? Is is possible for the pump to be working but not at enough capacity?

SWEI

Put a torch on the pipe near the pump inlet and see how long it takes for the pipe to cool down after you remove the heat.

njtommy

Are you amble to check the voltage or amp draw at the pump?

stephen11962

Voltage yes, amperage no - not sure how to do. Have the meter thought.

njtommy

I would check to see if the motor is very hot to the touch and check voltage to it. Also if the boiler is off for a while does the supply and return water temps seems to be close in temp?

stephen11962

Prior to posting here, I called WM to try to talk to someone. They were busy then and finally called back a little while ago:

They indicated that the Taco circulating pump was probably the problem if every thing else seemed to be normal. So, I ordered a replacement cartridge on line. Three supply houses in my area do not stock this item (Taco 0014-004RP) so I have to wait for the UPS man. WM said that the wait should not be a problem since the b-25 error code indicates that the boiler is "protecting itself" by shutting down and would reset itself in 10 minutes.

I'll report the results. Thanks for all suggestions.

S

SWEI

A 0014 is a lot of pump. You might be able to get by with something smaller, which would cost less both to buy and to operate.

kcopp

Grundfos 26-99 would work... speed 2/ medium

4Johnpipe

How's the heat exchanger? Clogged heat ex will mimick bad pump.

unclejohn

Whats the delta T at the boiler. does and rads or baseboard heat.

stephen11962

Back again...
-Pump size is pretty much fixed - unless that can be changed without removing the whole pump assembly. Change out the cartridge is 4 bolts and some water on the floor.

-Heat exchanger? Boiler powers radiant heat in concrete slab (3,000sf), hot water storage and FTR on second floor.

-Delta T? Do not have thermometer for that

S

lchmb

has the system been serviced?

stephen11962

Back once again. Responding to comments above:
Boiler pump sized by WM, came with boiler.
Pump is often very hot, water circulating in loop can reach 180 degrees and whole pump assembly is in intimate contact with piping.
Radiant heat works, but is low temp and does not trigger error, b-25, too fast rise in outlet temp.
The new cartridge did not make a difference. Lost $$$.
Talked to WM again. Said to check outlet water temp sensor. Bought new one at $13. Installed. First observation, everything seems to be OK, but I am skeptical. Too easy a fix. Have to wait for several more cycles.
Boiler still makes loud clicking noises (new the last 2 months, with error code?) that come from the boiler itself. Putting the boiler cover on significantly muffles the noise. Tried locating source by touching various parts with metal rod (too hot to touch). No luck. Frustrating job. Have to wait indeterminate time for the next noise.
S

Tom_133

Sorry stephen, without tooling like a amp probe, and an ohm meter it's hard to nail down pump or sensor. That code is either supply or return sensor, bad pump, or bad control, typically. It can probably show up with a host of other ones, but those are the trouble makers.

KCA_2

Interesting! I know someone here by me that has a very similar issue.... :-))