2nd light duty fail

Projectman

Hoping you guys can help with this. I installed a PH76-60 2 years ago to supply my radiant heat and DHW. I did all the plumbing and radiant install. Not a plumber or heating guy but a 30 yr exp remodeler with lots of plumbing experience and worked with my plumber along the way. The supply for the heat and HW is great. Virtually unlimited HW even when all zones were calling fo heat. Problem is the first unit failed and leaked into burner just at 1 yr. HTP replaced under warrantee. I reinstalled and now just over a year, water is coming out of the exhaust pipe and tank is again leaking. Both units have been serviced by HTP factory guy all along. We can’t understand what is happening and why 2 tanks have failed. I’m including a picture of my setup if you guys can see anything that would cause this. Factory guy is working on getting me another unit again but the 2 failures are scaring me to reinstall yet another one. He assures me that this is the only time he has heard of this.

clammy

the heating side is seperate from portable water correct .The only thing i noticed is heating system expansion tank location it s usually located on the suction side of the pump and in the pic the handle is closed .I would check your portable water pressure and make sure that portable expansion tank is propely sized for your tanks volume and has the correct pressure .Any clues from HTP on weather its portable side or boiler side that is failing . On another note is that oxygen barrier pex and what is the max temp the unit is suppling and are u using the outdoor reset and has the controller been programed post purge on pumps and such aslo why the portable expansion tank on the heating side .I noticed the vacume relief valve but do not see a portable nor heating safety valve maybe i m just missing it and what pressure are you running the portable and heating side at .Peace and good luck clammy

Projectman

The heating side is separate from domestic. There is a heat exchanger left if the water heater.

The picture was taken around install time and the handle for the expansion tank has been open.

Yes, Oxegen barrier pex.

As I remember the tanks were sized.

Usually operate unit at 130. Just got outdoor reset a month ago to install. When single digits out, i manually turned up the temp to 140. Kept house nice.

By heating safety valve did you mean t&p. Located in the back top of the tank.

Running heat side at 12PSI, domestic side is 62psi for a Gould constant pressure pum from my well

Fred

"Well" may be a clue. Have you had the water tested?

Larry Weingarten

Hello, Do you soften the water?

Yours, Larry

Projectman

Forgot to add another pic. This is the right of the heater and supply lines to the house. The empty manifold is future 3 zones for the finished room opposite the wall. The tank is an acid neutralizer.

Fred

The first failure may have been considered a fluke. The second failure (in about the same amount of time) verifies that it was not a fluke. I would figure out what the problem is before I ever considered installing a third unit. My guess is there is a significant problem with the water. Something is pretty aggressive.

Projectman

I agree that it is not a fluke. Water is well water. It was tested and found somewhat acidic but not terrible on the ph scale and hence the acid neutralizer. That’s why I posted here. Company rep sees nothing out of the ordinary and my plumber has looked at it and says the same. Meanwhile it’s cold water showers until something gets figured out

Fred

Do you know if the leaks are on the heat side or the potable water side? Was that consistent with both failures? Is everything grounded well?

Projectman

Not sure I understand. It’s a water heater and the water is leaking internally into the burner and running out the exhaust pipe/condensate drain. It is the same thing that happened with the first one. The heating chamber was full of water and hence the error codes and it would not light. That’s how both times came to my attention.

All the electrical is grounded. Including the submersible pump. The copper plumbing is not grounded since there is plastic and pex lines coming from the pump to the copper manifolds.

Why would that be an issue. Perhaps I missed something

Fred

That unit has to have a separate coil or some type of seperation inside it for potable water. Potable water has to be separate from the water in the portion that heats the house. If it leaks on the potable water side, that is an indication that the water supply may be an issue, given the amount of fresh water that flows through that portion of the heater. The portion that heats the house is not new water. It is the original fill that gets heated and recycled through that system so there would be far less effect on that portion of the system.

There has been a lot of discussion on here recently about stray electrical current and how it can cause pinholes. Here is one link. Search on "Stray Current" for other discussions as well:
https://forum.heatinghelp.com/discussion/comment/1517114#Comment_1517114

Projectman

Fred, everything in the hot water heater is potable. The heating side is after the 40 plate heat exchanger which is on the left side of the water heater.

The water was tested. It is a ground water well and not hard, just slightly acidic so the water testing company suggested the acid neutralizer which has been installed. It was just put in place when the picture was taken. That’s why it is not plugged in. Because it is ground water, there is some iron coming through. I have installed 2 sediment filters. You can see that the one in the picture is in need of changing which I do pretty regularly.

Thanks for the link on grounding. I will check it out. It may be a good idea to run a ground wire to that side of the plastic well line run.

hot_rod

Check the chloride levels also. Stainless is somewhat sensitive to elevated levels.

When you soften water you end up increasing the conductivity. Increasing conductivy can increase certain types of corrosion, especially between dissimilar metals. The elevated conductivity becomes a stronger electrolyte. Even like metals in the presence of a strong electrolyte will increase dielectric corrosion.

The CDA talks about corrosion between brand new copper and old copper when a strong electrolyte is present, it does not need to be disimilar metals to cause this type of corrosion.

The ion exchange (softening) does remove most of the scaling ions, a good thing, but in the process adds sodium, depending on other conditions, that could actually be worse for the tank.

Also here is the water quality spec from one of the HTP installation manuals.

Consider sending a water sample to a lab to see exactly what the levels are, of the various components of the fill and domestic water.

hot_rod

Some additional water quality info here.

https://www.caleffi.com/sites/default/files/coll_attach_file/idronics_18_na.pdf

Projectman

Thanks for those links hot rod. After reading the water quality report, though I was lost is some of it, I’m convinced that 98% of hydronic systems around here are screwed!

I checked my water test done last year and the TDS was 210and the PH was 6.1. Hardness was 34.2 ppm or about 2 grains. Again, no water softening involved in my system, just acid neutralizer to bring up the ph

nicholas bonham-carter

How does this “acid neutralizer” work? Once the heating side of the system has been filled, the water will stay in the loop for the life of the boiler. Usually any adjustment of the ph of this water will be made at the initial fill, using some chemical cocktail.
I wonder if the neutralizer could be responsible for some stray current which is causing the pinholing.—NBC

hot_rod

Projectman said:

Thanks for those links hot rod. After reading the water quality report, though I was lost is some of it, I’m convinced that 98% of hydronic systems around here are screwed!

I checked my water test done last year and the TDS was 210and the PH was 6.1. Hardness was 34.2 ppm or about 2 grains. Again, no water softening involved in my system, just acid neutralizer to bring up the ph

Certainly a lot of different opinions on boiler water quality. All agree the scaling minerals need to be at a low level.

Disagreement on the method to clean up water, however.

Some suggest softening, removing scaling minerals is most important. Others propose DI or RO water as it removes additional ions, the cations or positive charged ions, a that can cause corrosion, chlorides for example.

If you boiler has a chloride level indicated, most aluminum and stainless boilers and tanks do, softening may not be the best option. Some suggest the softener needs to be set up properly to avoid adding too much sodium. More expensive softeners have multiple settle and flush cycles. Different offices are avaliale for the brine port, it should be sized to your water hardness, ideally, no need in dumping excessive brine down the drain either. Sample your softened water at a lab, determine what your softener is leaving in the water.

The German VDI standard for boiler water suggest not adding conditioner chemicals if the water is dealt with first.
Other suggest the chemicals add additional important benefits like Os scavengers, ph buffers, film provides, etc to protect the system since O2 is tough to keep out.

Slant Fin released a comprehensive water quality guideline last summer, the suggest hard water is preferred to soft water, below 11.7 gpg. They claim softened water is "old school" The first boiler manufacture I know of that addressed water to this degree.

So a confusing amount of info out there.

I suggest TDS 30- 50 ppm. DI or RO will pull cations and anions so you end up with close to pure water. If your TDS is 210, and it is high in chlorides, I'd look there for the cause of failures. The TDS number does not indicate WHAT is in the water, just the level.

For example, adding a conditioner chemical may drive the TDS number up, but you have added good stuff to protect the metals, so you need to know what was added on the first fill and if the junk was cleaned out of the boiler and piping.

Some feel this DI or RO water is to aggressive as ph will be in the 6's. We have found within a week that ph buffers back to mid 7's by pulling some metals from the system components. OR add conditioner, if that low ph concerns you at the fill to buffer that ph and add ingredients mentioned above in the inhibitors, Rhomar, Fernox, Sentential are some of the common brands.

The system MUST be cleaned first however or the oils, flux, pipe dope etc will react with inhibitors, or provide a food source for microbial corrosion.

A pretty complex subject, especially when troubleshooting failures that may be water related.

Sam81

I have been struggling with bad seals on pumps leaking heat exchangers on boilers in a commercial hotel, back-and-forth I ended up just adding Fernox inhibitor, cleaned and flush the system with Fernox cleaners, since then I haven’t had anything leaking so far,

Projectman

The acid neutralizer is the tank of calcium and calcite that the potable water runs through and it brings up the ph. It does harden the water slightly but according to the water test it is still within acceptable levels.

Projectman

If I remember, when the initial fill went into the closed system after the heat exchanger, this was not installed. Remember that the trouble here is on the domestic side in the hot water tank somewhere in the heat exchanger where water is getting in somehow.

clammy

I know this sound s totally stupid but did anyone verify that the tank is leaking by isolating and watching tank pressure drop on a gauge and that this not just condensate not draining properly ? Know that sounds stupid but ya never know.I ve seen things that silly not Otherwise i would surely guess its a portable water quality issue .Too bad the flat plate wasnt producing domestic hot water that way when it fails u just change the plate most likely cheaper then a new boiler peace and good luck clammy

Projectman

Nothing here is stupid clammy except the fact that two units have failed. I did check. When it kept coding and not starting, I looked some options. There is a short piece of clear tubing coming from the condensate filter and I noticed that there was water in it the condensate drain has a good pitch so I took it apart. Water kept leaking out and I thought it might have backed up but it kept coming. I filled up half a five gal bucket and it wasn’t stopping. Then I took apart the PVC exhaust pipe and water was coming out that pipe from the unit. After 10 gal of water and still coming out, it was obvious that the water was just no condensate backup. So now to figure the reason that t exchanger is leaking and what is broken.

SuperJ

Any chance your intake is sucking debris in and fouling up the burner (on the combustion side)? Seems like a major downside to the tank type boilers (Pioneer/Polaris) is that the burner isn't really serviceable.

Projectman

Just had the water heater serviced a few weeks before because it is the end of heating season. He pulled the burner, checked inside the chamber, set all the settings with the combustion analyzer. Said everything was wirking fine. Spent over an hr going through everything. He’s a trainer for HTP so I take him at his word.

Thanks to all of you so far for the input. Seems like no obvious things yet. Service guy is checking with the HTP tech guys

bob eck

Is this tank SS?
What type of fittings are connected to the SS tank? Copper male adapters, black steel nipples, brass nipples or SS nipples?
HTP builds SS electric water heaters and they have special (don’t know what type of material the threads are made out of) and you need to use their replacement elements you can not use regular water heater elements because they are dissimilar material and will cause the tank to leak. I would check with HTP and ask them what type of fittings can be used to connect to their SS tank. That could be causing the tank to leak. Take photos of where the tank is leaking and get them to HTP technical and see what they have to say. What is the cloridies level in the water. Cloridies can kill a SS tank real fast. If it is cloridies causing the tank to fail that would not be a manufactures defect.