Questions about my new MegaSteam installation

Phil_17

My service company recently replaced my old boiler with a new MST513.

Motivations to replace the old boiler included a distinct lack of heat in one branch of the house and the obvious problems with the near piping of the old unit (pictures). The install went smoothly and the near-boiler piping is a clear improvement over what was there before. The main part of the house heats great, but now I've got some banging in the troublesome branch (that's new) and very little heat.

I have mostly convinced myself that the horizontal runner to the non-heating rads is undersized and/or inadequately pitched (perhaps I'll ask about that another day), so this is a separate issue from the new boiler, but I want to make sure that everything with the new boiler is minimizing my problems instead of contributing to them.

My questions/issues (in no particular order)

Vaporstat: I asked for it, and offered to pay any difference, but they said it wasn't worth the money. I've got the pressuretrol turned down to about 1/2-3/4 lb (they set it at 2). The boiler definitely is cycling on pressure when it comes out of overnight setback. Should I be insistent about this.

Near boiler header: I am wondering if it wouldn't have been prudent to go with 2 1/2 here (drop header would have been nice, but I forgot to mention it before). The MST manual says 2" minimum for the 513, but 3" minimum for the 629. Could this header be undersized and contributing to the banging out back?

Main take-off: Aren't these supposed to go vertical to make dry steam?
I'm thinking that I may be getting a lot of water in the second take-off and that this may be contributing to the banging and no-heat problem.

Equalizer: What are your thoughts on the zig-zagging pipes above the water line? I thought that this needed to go straight down as far as possible before moving around to line up with the returns.

Hartford loop: No valve to enable flushing the returns.

Skim port still plugged: And it hasn't been skimmed (I know this must be contributing to the banging). If they had put a pipe and fitting in there, I'd happilly skim it myself.

Indirect pump for the DHW: This is way too far off the floor. How long before I start having problems with the impeller.

Others??? What else do you guys see that I'm missing? Which of these issues is worth getting worked up about and which ones are not worth losing sleep over?

Thanks in advance,

-Phil

Unknown

Phil

In response to your questions, I offer the following.

Vaporstat - If you have a system which is conducive to operating at minimal or ounces of pressure, then a Vaporstat is a good idea. Otherwise I would stay with the conventional pressuretrol supplied, or short cycling of the burner and related controls may prevail.

Near Boiler Header - I wouldn't be overly concerned about the header size on this one.

Main to System Risers - Although vertical risers from the header to the system are desirable, I'm not concerned in this case because you have enough vertical rise (probably 12-18") and pitch on those angled risers to keep the wet steam back down at the header. The equalizer (which you did not have before) will direct that condensate back to the boiler properly.

Equalizer Piping - Provided the offset that was installed has pitch toward the boiler, I would not be concerned about the offset.

Hartford Loop - Although in a perfect world, a provision to be able to isolate and blow out the return piping would be desirable, it is not an absolute necessity. We have been showing that provision for a number of years in the manual but very few ever get installed. The requirement for this depends a lot on the system and the amounts of wet returns. Most systems with mostly dry (overhead) returns bring back very little debris that needs to be flushed out. Systems with wet returns, however, are a different story.

Skim Tapping Provision - We and most other manufacturers provide a plugged tapping for skimming the boiler. Our advice on this, for safety concerns, is to install the nipple when skimming but not to leave a provision for anyone else to possibly open a valve or remove a cap and get scalded. Skimming is something that is usually done either at startup or after a short period of operation if debris and oil collects in the boiler. Oil on the water surface can contribute to the banging you are hearing but mispitched or sagging pipes are usually the cause.

Indirect Pump Location - We do show the pump being installed well below the boiler water level. This will ensure it doesn't encounter steaming water or even a slug of steam if your water level surges due to dirty or oily boiler water. When you try to pipe a boiler and only have so much space to be able to squeeze in this many pipes in a confined space, things like this occur. I see literally scores piped this way with no operational problems that I ever hear about though.

Over all, you have a very good installation here. The installer, for the most part, stuck with the recommended methods shown in the installation manual. System issues, such as banging, happen on countless jobs, but are just that.....system issues. Things like this do show up with a new boiler only because the new boiler is making steam much faster than the old boiler.

Your installer gave you several extras that others would never have. I can see some of these in your pictures such as those nice Gorton Main Vents and what appears to be painted near boiler piping. It seems obvious that he cares about what he does and that tells me that he will more than likely respond to your wishes regarding the banging and other concerns you have. Thanks for using the MegaSteam boiler and I'm sure you will get many, many years of efficient operation from it. Hope this helps.



Glenn Stanton

Manager of Technical Development

Burnham Hydronics

U.S. Boiler Co., Inc.

Phil_17

Overall, I've been very happy with this installer

They did the painting, but the Gorton's were my work, attempting to get heat distributed as evenly and efficiently as possible. They're about 12 months old.