Lots of Water Hammer and Surging

cobyschaef

Looking to make sure I'm going the right direction here. I had to add some water to my one pipe system. Not an excessive amount, just enough to bring it back up the the normal level. After doing so, I started to have a lot of hammer in two or more of my radiators whereas there has been no hammer at all since starting my system and fixing a few issues back in October and November. After a week or so, I went downstairs to check it out. As I watched the system run, I was getting an excessive amount of surging happening. The gauge glass was dipping by almost half at certain points. I figured it may be related to using a bit too much 8 way treatment with a system that is probably still relatively dirty. I ended up draining some water from the mud leg and refilled but without adding any more treatment, to dilute the pH level a bit. It was somewhere near 11 as best I could tell. This seemed to help but there was still some water hammer going on and it was gradually getting worse. I ended up draining a bit more water and sludge from the bottom of the boiler then proceeded to skim the boiler for a few hours suspecting that there was probably oil in the system. To my knowledge my system has had very little maintenance over the last 10 years under a previous owner, so it's probably overdue anyway.

So I'm looking to see if I'm going the right direction. I'm planning to skim some more since there still seems to be a thin film of oil on top of the water. As far as I can tell, this started afternoon refilling with some distilled water.

Everything else in the system is working properly, LWCO, pressuretrol, etc. But I'm happy to give any more details that may be needed.

Captain Who

What is your water source? City water I presume but I mean is it known to be alkaline, high hardness, high alkalinity? Those could've driven the pH higher and maybe TDS (total dissolved solids), which you want below 2000ppm or so (too low can be bad too but don't worry about that unless you have a super clean boiler and super pure distilled water and bad near boiler piping….pretty uncommon).

I suspect your TSS (total suspended solids) could be too high, from rust particulates, along with a pH of 11 being on the high side which could contribute to foaming. Over 50ppm would definitely be the danger zone but it is hard to measure unless you are, like, a lab nerd.

If you have a dirty unmaintained system I'd be willing to bet that what you need is a good drain and reverse flush; both the boiler and returns, and I'd do it until the water looks pretty darn clear.

Jamie Hall

Too much water treatment. Drain down completely and refill with good clean water. Skim until the surface is clear.

Don't do this when it's cold out. It will probably take hours…

ethicalpaul

I don't think it takes that long and I prefer the temperature dropping a couple degrees in the house rather than deal with carryover.

Drain down completely and refill with good clean water. Skim until the surface is clear.

I suggest the inverse order. Do your skimming first when the water is nice and hot—then drain and refill after that. It's usually good to skim after the boiler has been sitting still for an hour or so to let the oil float back to the surface.

You don't have to drain the returns, only clean distilled condensate is in there. Let the Hartford loop do its job to separate your boiler from your return lines.

Note that 8-way has a pH buffer, so you can't really partially drain and refill with water and expect the pH to change very much. The chemistry is such that it "tries" to keep the pH at a given level.

Also (and I only found this out some months ago), pH test strips should be used on boiler water that is cooled to room temperature. If you test hot water you'll get a high reading. I will bet the actual pH is not as high as you indicated.

Don't worry, you'll get there. 8-way does free up old gunk which adds to the solids in your water, as @Captain Who said.

cobyschaef

Thanks everyone! I have pretty hard town water, about 14gpg or 240 ppm and it is not alkaline. I have a softener but don't use it to fill the boiler. When I turned the boiler on last year, I gave it a skim as well as several flushes since it was very dirty. I then refilled with my normal town water and added some 8 way treatment. As far as I remember it was about 9 or 10 pH when I first added it. I don't know if I can even wait until its warmer to do this. We've been consistently getting below zero and yesterday before skimming it was literally inoperable. As soon as it started to steam it threw nearly all the water into the mains. The header piping is also not correct, I know, but that's not something I'm looking to fix in the middle of winter. Currently, it functions, so if I get a warm enough day or two I'll give it a thorough skin and flush. I also don't mind refilling with distilled water after flushing, assuming that should help.

Captain Who

If you can call throwing nearly all the water into the mains functioning 😀 I've been there in the past so I feel your pain.

I'm currently getting very stable operation with less than 1/4 in. of sight glass surge, with pre-boiled distilled water treated with 8-way, but only after the draining and reverse flushing. I do indeed have lots of mud in my return so everyone's situation is different apparently.

I would suggest getting a full port ball valve for the drains, especially the boiler one which will probably be the dirtiest. That lets you get some velocity, both on the draining and on the reverse flushing. I use a short length of hose from my utility tub faucet to the boiler with a shutoff ball valve at the boiler end of the hose. That lets me take it off the boiler without making a mess of the floor and also lets me re-attach it with the ball valve closed, open the boiler ball valve, and then the one on the hose to do the reverse flush.

ethicalpaul

@Captain Who and I both use pre-boiled distilled water, but you don't have to in order to get good results.

And you shouldn't need to skim unless oils have gotten into your boiler—it's not a regular thing to have to do.

The quick and dirty way to see if you can get things calmed down with minimal downtime is just to drain all the water out like @Jamie Hall said. (and as @Captain Who said, some velocity is good) and then refill it.

Fresh water is bad, but carryover is worse in my opinion. Then you can try the 8-way again when things are warmer. Always start with just a very little to see how it does. Like a cup.

And as you and I have both found @cobyschaef, boilers with bad piping don't initiate carryover—they can run fine if the water is good. Carryover is initiated by bad water. As I have done more experiments over the years I realize this more and more.

cobyschaef

https://forum.heatinghelp.com/discussion/comment/1886257#Comment_1886257

I didn't say it was functioning well 😅

It's night and day compared to what it was doing yesterday, though! Thanks for the input. I'll have to see about giving it another good flush.

cobyschaef

https://forum.heatinghelp.com/discussion/comment/1886258#Comment_1886258

I'm sure that some has gotten in, if there wasn't some in there already. I did a little bit of piping work when turning it on for the season, so I wouldn't be surprised if some more had accumulated. I'll try going easier on the 8 way, too.

ethicalpaul

OK in that case, skim away! That pipe work is probably related to your new carryover issue.

AdmiralYoda

This happened to me as well when I first started using 8-way. 45 year old Peerless that was not well maintained before I got it. Poorly piped as well but works great aside from being oversized.

I added the 8-way to a freshly tuned up boiler. Using about 1oz per gallon which isn't really excessive and gave me a pH of about 10.5.

After a couple weeks the water was clean but turned cloudy. I assume this is scale and other "non-mud" stuff that got dissolved. For the first time ever I heard the characteristic water hammer! I went down to the basement to discover most of my boiler water missing up the mains!

I drained the boiler, added more 8-way and let it go again. It happened again, but this time after about 6 weeks. Drained and filled with fresh water and more 8-way. Hasn't happened since!

I'm assuming it was the junk that got dissolved/dislodged that caused the surging. Now my water is crystal clear (but light violet) with no cloudiness and never surged ever again.