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Triangle Tube Solo 110 PT internal pump fail , replacement ?

vicbrick Member Posts: 20
Installed TT solo 110 PT with Trimax controls over the summer.

Intermittently over the past couple of months, when the thermostat would generate a call for heat, the boiler would run/initialize for few minutes then shut down, with a "CH demand setpoint reached" message. Outlet temps around 130-135F and inlet around 65F Hmm, not good, but eventually the boiler would restart and perform well.

The problem has continued to get worse and I have been able to determine the boiler is sending the signal/current to the pump (set on low speed 1), but the pump doesn't run, the burner does fire thou.... However, the pump does work fine on both the higher speeds.
(in the installer menu, you can manually turn the pump on/off while varying the speed on the pump..nice way to test)

So with a whopping 373 hr of CH run time on the pump, it appears to have puked out the lowest speed.

I am not a professional installer, so I don't want to fight with Triangle Tube for a warranty claim...beside I might have caused part of the issue by leaving toomuch air in the system and damaging the ceramic bearings?...who knows)

The internal pump in my boiler is a Gundfos 15-58F PN 59896759 P1. If I pull the flow check out of an "off the shelf" Grundfos 15-58FC, will it bolt in directly?

Thanks! any other ideas appreciated as well.

( if curious, pixs of my install are also on this forum in a different thread)


  • vvzz
    vvzz Member Posts: 39
    edited December 2015
    That's troubling how the pump failed so fast. I also don't think boiler is able to modulate the internal pump speed - only on/off within the pre-set pump speed. The only thing that can be controlled like that is the fan.

    For what it's worth, my boiler came with the union connection between the heat exchanger and the internal piping loose. When I filled up the boiler and water started leaking it caused me to freak out for quite a bit until I tightened the union. Triangle Tube starts to worry me. But then again - you don't really hear about things working well.

  • Zman
    Zman Member Posts: 7,446
    An off the the shelf 15-58 will bolt right up. Depending on how you are piped, you may want to keep the check valve.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • hot_rod
    hot_rod Member Posts: 19,279
    Often times it is easier and quicker to remove the 4 allen bolts and switch just the motor, don't disturb the gaskets.

    But find the cause of the failure, if it is just one speed, it doesn't sound like a piping or air problem, just a bad switch.

    Is speed 2 an acceptable option?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • vicbrick
    vicbrick Member Posts: 20
    Thanks for the input, always appreciated! Have a replacement 15-58FC pump from SupplyHouse enroute.

    Not sure what caused the pump failure on speed 1, but think it would be a good idea sort it out . During the install, each radiator circuit from the manifolds was filled/purged separately, with all the other circuits closed and the pump off...however, it did take quite a while (many days) for all the air/ "noise" to disappear from ~ 2,100 ft of PAP tubing when I brought the system on-line.

    What is interesting. If I place the pump speed selector switch in position 2, and turn the pump on/off via the installer screen ...works fine. If I start the pump in position 2, leave the pump running and move the speed selector to position 1, the pump will continue to run fine at the lower speed. However, if I turn the pump off and try to restart it at the lower speed I just selected, it will not start/run.

    So, I tend to think the switch for speed 1 is ok. but for whatever reason the pump doesn't generate enough "starting torque" to run at the lowest speed....so, I either have a higher static friction issue (bearing, contaminate?) or the EMF has decreased.?

    Yes, speed 2 is ok...In my mind, just pumps more than required...

    Has anyone ever the replaced the standard 15-58F pump with the 15-55 Alpha pump? For a variety of reasons, I think that would interesting ...just not sure I want to be the guinea pig ;0


  • hot_rod
    hot_rod Member Posts: 19,279
    If the curve for the Alpha matches up with the boiler requirements, it would work fine in a fixed speed mode. The ECMs are DC motors and have a lot more starting torque.

    I have switched out 15-58 with Alphas by just pulling the motor, leave the volute installed. I'm not sure the manufacturer approves, but my manual flowmeter indicated they perform just fine. I have used Alphas on the coil type boiler HXers also, like Munchkins and Knights, etc.

    I'd wonder why air elimination is taking that long. With a good micro bubble air separator, installed properly at the hottest point in the piping, a day or two to completely purge all air, even micro bubbles. Glycol can take longer to de-areate.

    Check all the wiring connections to the pump. Sometimes the strands under a wire nut break off, the wire reads voltage but may not carry enough current for the starting draw.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • vicbrick
    vicbrick Member Posts: 20
    Hot Rod

    Thanks for the additional information and guidance. Once winter finally arrives and I have a chance make sure the new system satisfies the heat demands, etc. of the old house, I will change out the 15-58 for an Alpha. Think that will be a nice/fun upgrade.

    I suspect there are multiple reasons why air has remained in my systems longer that expected: My overall desire to direct pump through the boiler, reliance on the Sorbox as the only source for air removal, low pumping rates, etc.

    Overall, I think under estimating of the value that constant circulation would bring was my biggest "blind spot" in the system I selected/installed . The very old system I removed only fired and pumped when a call for heat occurred...so, I largely discounted the idea of a "paying to run a pump constantly" Thankfully, VVZZ and others on this forum have helped me to better understand the efficiency and comfort that constant circulation can offer.

    Having done a number of automotive/old house projects through the years, I knew it was likely that version 2.0 would materialize....I left as much " real estate" as possible between the boiler and the manifolds :smile:

  • vicbrick
    vicbrick Member Posts: 20
    Hey, just to confirm...the replacement 12-58 pump motor/cartridge bolted into the volute fine and has been spinning away for the past several days with no issues.

    Initially, I though the capacitor might have failed, so I switched out the terminal box from the new pump to the old....no dice, still failed to start on speed 1.

    To my untrained eye, the old pump looked and spun fine when removed...So the failure on speed 1 looks like it will remain a mystery....let's hope so ;)