Squealing Taco

Solid_Fuel_Man

Installed 4 years ago, Taco XPB and the injection circ is squealing at a certain RPM and seems to be sticking as the controller keeps ramping up and suddenly it frees up and overshoots target. The controller in turn, slows the injection circ and it sticks again causing the thing to go into oscillation. Supply house can have new cartridge for injection side by Wednesday. Is there anything I can do to avoid this, water chem is good. Running water w/o glycol on both sides of the HX.

Seems short lived as it only is used about 4 hours/day 6 months a year.

Taylor

Snowmelt

Did you go into taco flow pro with that question.?

Rich_49

Why not RMB without Glycol on either side ?

Steve Thompson (Taco)

Sounds like something is causing the rotor to drag. Might want to consider replacing the cartridge. You can send the old cartridge to me at Taco if you want a teardown done...

Dave H_2

It also sounds to me like a balancing valve would also help on the injection side of the piping.
There is a bunch of math that can be done to find where to set the balancing valve, but if this is your own home, the easiest is when you reach design day temperatures outside, the X-Block variable speed circ will try to and should be at full speed indicated by the bars on the controller. If it is not, close down the balancing valve until it does.
This will let the circulator and the controller do what it wants to do, if not, it will slug the system with hot water, the sensor then tells the controller its too hot, then slow down, then speeds up.....you get my drift.

Dave H

Solid_Fuel_Man

Ok, so I have the replacement cartridge, and my supplier said it is a 005-020RP and of course since I have it on the shelf it hasn't done it at all. Am going to replace this weekend anyway.

As for the balancing valve, it is piped off of the boiler's primary loop with closely spaced T's and generally runs in the 50-70% range. However I have it as a dump done and will add a resistor inline with the supply sensor and trick the controller into a lower supply temp and go 100% injection for a few min. No balancing (throttling) valve needed.

I think it's just a sticking cartridge. Is this just a standard 005/006 cartridge? Can I swap in something else?

Taylor

Steve Thompson (Taco)

I'll have to ask one our Product Managers and get back to you. Should be a standard cartridge but I need to know which one. Stay tuned...

Solid_Fuel_Man

Thank you Steve. Curious about using a different cartridge as well.

Taylor

Steve Thompson (Taco)

Product Management has suggested it might be the check valve at low injection RPM (but I still recommend replacing the cartridge).

It's a 008 Bronze cartridge.

Steve Thompson (Taco)

Part number is 008-045RP. It'll look a litter different (quite a few product improvements) but will work...

Solid_Fuel_Man

So the 005-020RP is not the correct part? I thought it was a 008 variant for the XPB. The 005 is for the RMB if I'm not mistaken.

Thank you for your help! It always seems like it's the stuff I have in my own house that gives problems. All the stuff out there I put in for customers just keeps on working. Or maybe it's the closer supervision here at home

Taylor

Solid_Fuel_Man

Are both the upper (V.S. boiler) and lower (system) cartridges the same part number? Just for future reference and to keep a spare on the shelf.

Taylor

Steve Thompson (Taco)

100% confirmed (sorry for the late response - was at the ASHRAE/AHR show).