HTP UFT 80 heat exchanger leak?

[DR-DEATH]

I had an HTP UFT 80 installed around November of 2016. I was in basement and noticed rust on the bottom and opened it up to see rust and corrosion around the gas line and black iron water inlets.

Immediately thought it must be leaking from the HX and noticed some corrosion on the bottom of the HX. We had the low water shut off sensor replaced a year or so ago as it failed and it looks like that has corrosion on it and right below that has rust colored corrosion below it on the HX. The opposite side of the HX has corrosion but it’s not chalky and not rust colored.

I’m now wondering if it’s leaking from the low water sensor after it being replaced. The company that installed it is coming out tomorrow to see if they can for sure see what’s leaking.

It was bone dry in there as well - just corrosion.

here are pics: https://imgur.com/a/fHwmCLs

 

[WorthFlorida]

The rust on the iron gas pipe looks like its from condensation. You just need a damp environment and any iron or steel will get surface oxidation. None of it looks like a leak. The first picture what looks like an aluminum pipe, a brass compression nut and a iron or steel fitting, that is from electrolysis. I would take a brass wire brush and clean it up to get a better look at it. It all seems to be on the surface only. The gas pipe does look like water hit it but is could be from above dripping with condensation. I see a lot of surface rust on the top sheet metal where the gas pipe fitting comes through. It all looks like condensation. If you had a leak it would be leaking all the time. There is a chance on very cold nights the heater increases the water temp to meet the heating load and internal water pressure increases. It might weep at a fitting somewhere.

Do you run a dehumidifier for the basement in the summer months?

 

[Sponsor]

 

[DR-DEATH]

The rust on the iron gas pipe looks like its from condensation. You just need a damp environment and any iron or steel will get surface oxidation. None of it looks like a leak. The first picture what looks like an aluminum pipe, a brass compression nut and a iron or steel fitting, that is from electrolysis. I would take a brass wire brush and clean it up to get a better look at it. It all seems to be on the surface only. The gas pipe does look like water hit it but is could be from above dripping with condensation. I see a lot of surface rust on the top sheet metal where the gas pipe fitting comes through. It all looks like condensation. If you had a leak it would be leaking all the time. There is a chance on very cold nights the heater increases the water temp to meet the heating load and internal water pressure increases. It might weep at a fitting somewhere.

Do you run a dehumidifier for the basement in the summer months?

The boiler is in a small room with a door that leads to a storage room. We do not have a dehumidifier in the storage room or boiler closet but have one in the main basement. Approx 500sqft between all spaces. I do put rid x buckets in the storage room and boiler room to help with moisture. The boilers been installed for 4 years and we have never seen this rust or corrosion ever. The biggest reason I originally thought it was from the HX was because the corrosion around the bottom of the HX.

 

[Arseniy M]

Here I am planning to install this bad boy. Would be curious to find out what the source of the leak is -- hopefully it's just condensation.

 

[DR-DEATH]

I have been very happy with the boiler. Been in service for 4 years and only had the low water cut off sensor crap out after 2. Part was under warranty but only costs a few bucks anyway and easy to replace or cheap to have a plumber install the part. I honestly think the low water sensor wasn’t tightened all the way and slowly leaked causing humidity to rise and rust those areas. I really don’t think it’s condensation at all though.

 

[DR-DEATH]

I sent the photos to HTP support. They said there’s signs of a heat exchanger/internal exhaust has failed based on the white corrosion on the right side of the heat exchanger.

There’s 100% corrosion on the low water sensor and in the picture you can see rust on the wires below it - which are above the bottom of the heat exchanger. I guess I’ll have my plumber replace the low water sensor again and wire brush the rust and corrosion where I can and watch it closely.

 

[Arseniy M]

I would think that if the heat exchanger was cracked and leaking, you would have been able to notice puddle of water inside the cabinet. Even a few drops would become apparent very quickly. Fingers crossed, hope the HX is ok. Maybe you can shut off the boiler feed and see if pressure drops?

 

[DR-DEATH]

I would think that if the heat exchanger was cracked and leaking, you would have been able to notice puddle of water inside the cabinet. Even a few drops would become apparent very quickly. Fingers crossed, hope the HX is ok. Maybe you can shut off the boiler feed and see if pressure drops?

Yeah I would think so too.
There’s rusty water spots on some of the wires directly under that sensor that are above the heat exchanger bottom. How would those get wet/water spots if the heat exchanger was leaking? Water doesn’t go uphill so I’m still sold on the water sensor leaking. I’ll just have it replaced and wire brush any corrosion and keep an eye on it every day.

 

[DR-DEATH]

I found a better picture of the old sensor and new sensor. The old sensor and new are identical but the old sensor was definitely screwed in more than the new one. There’s at least 3 threads still exposed on new one. Here’s a pic: https://imgur.com/a/RG4B3Xh

guess that could explain why it’s leaking maybe

 

[DR-DEATH]

So plumber was here and within 20 seconds he said it was a failed heat exchanger. He didn’t even look at the leaking sensor. He called HTP and HTP is going to do a full replacement. (Whole unit) at least 1k in labor. I’m not sold it’s the HX. Since it’s marked to be replaced I cleaned off the sensor and tightened it from where it was. It could be tightened at least another 3 FULL turns and now is seated like OEM. I wire brushed off any rust and corrosion and cleaned out the bottom area and put a water sensor where it looks like water pooled. Think I’ll just keep an eye out before we replace cause I’m not sold it’s broken.

 

[Arseniy M]

Ugh... Sorry to hear that, man. Again, for me the true test would be if the boiler loses pressure. If you have a shut-off valve just before your pressure reducing valve, I'd shut that off and watch the pressure for a day or two. If it's not dropping, I'd have to call BS on the HX diagnosis... There could also be a leak (less likely) somewhere in your heating loops. This would cause system to constantly add water -- not good, especially for these paper-thin heat exchangers.

 

[DR-DEATH]

Just wanted to add an update… boiler is still going strong. No more rust or water leaks since tightening the pressure relief valve.

 

[Fitter30]

Was the hx ever cleaned with vinegar? How often? It will be interesting to see the inside of the piping.