NTI TX151c bad Integrated Water Control

hilltop

Hello,

I had a tech over to service my NTI tx151c boiler, a cleaning was required. While here, he observed that the IWC is "going bad" and suggested replacement. I'm not sure what lead him to this conclusion, but he said its a fairly pricey fix. How can a bad IWC be diagnosed? What are the typical symptoms? It appears that the IWC has a little blowoff valve on top- on my unit it looks like it had blown fluid off in the past, the dried brownish crust around the blowoff is clear evidence. Is that typical of a failing IWC? He's pushing for a whole new boiler to be installed- am I being fleeced??

GGross

I never heard the term IWC before, when I google it it comes up with basically the entire block that handles DHW, sure could be expensive. How old is the boiler? can you take pics of the IWC in question and show the blow off valve please? if its just an air vent you may be able to replace that with a generic air vent, if there is a pressure relief valve in there that part needs to be replaced if it operates due to pressure. If you are over 10 years its a good idea to start stashing away for replacement if the internals look like they have been leaking.

hilltop

The tech found out this unit was manufactured in 2016, we purchased it with the house in 2020. Since we’ve been here we only use this boiler for 2 months/year for our radiant heat, so it mostly sits idle- this too may be a problem? DHW is supplied by a separate tankless water heater system.

GGross

I'll be honest this isn't terribly concerning to me. I might tighten down that cap as much as I could. Keep an eye on it for sure, I would be trying to get quite a few more years from it unless there are other serious issues. Sitting for extended periods of time generally doesn't hurt the water side, which you are looking at, I usually just worry about fire side issues from sitting unused. birds, bugs, and little critters can sometimes get in the vents and cause issues, they can do that when it doesn't sit for extended periods of time as well so not a huge issue as long as it gets used every year for a bit imo.

hilltop

Thanks for the response. And you’re spot on re: insects getting into the exhaust/intake. The initial reason I reached out for service was due to an unbelievable amount of flies/ladybugs within the combustion chamber upon startup, resulting in the entire condensate drain clogging with a literal handful of cooked dead fly mush.

mattmia2

Looks like that automatic air vent comes apart for cleaning, probably clean whatever is in the seat out of it and the problem goes away. It isn't a standard vent so you'd need parts from nti to rebuild it. Don't do it during the heating season in case you have to find what size o-ring is in it and order one rather than buy it from nti.