Heating Help

Boiler or piping issues

This one is from the fall of 2008. Client said he needed a new boiler. I did a connected load vs. heat loss to determine the boiler was sized properly. Reworked the piping and pump and it was awsome last winter.

Nice work!

Had a similar job, posted recently.  Sometimes a piping overhaul is all that is needed.  

Just Curious

While you were re-piping this system, why didn't you move the zone valves to the supply side?  Also what are those large pipes hanging under the floor joists.  Just trying to learn all I can.
Rich

Nice looking copper job

But here are a few ideas for next time, if you dont mind me saying. Move your pump to the supply side pumping away from the expansion tank. Dans book 'Pumping Away' will explain why. Move your zone valves to  the supply and you wont need flow valves. The way you have it now you may blow the relief valve because you are piped into the back of the pump with your auto fill. You can skip the air separator, The boiler is your best separator where you have the air vent, just put aT there and pipe the bullnose to the exp tank. You have 4 zone valves there. You need to control the flow through each valve, get a copy of Caleffi idronics 5 and figure your best option. Flat curve pump, Pressure bypass, ECM Pump. Those are the basic things, There are other points that will be made here that are debatable such as boiler protection so I will skip it. Your workmanship is neat and the job looks nice. I am not trying to be a prick here, just pointing out things that will help you in the future.

Thanks

I'll pump away next time. Why not zone valves on the return? It's a valve right. It never has blown the pressure relief, why would it? The autofill is in the bottom of the air seperator not the inlet to the pump.
Anyhow, it didn't work before I got there and now it does.

I didnt look close enough

At first it looked like the auto fill was going into the back of the pump. When you pump toward the exp tank, you move water with a negative pressure and piping into the back of the pump where the pressure drop can fool the feed valve into letting in a little water, but you didnt do that, my mistake. The  zone valves on the supply will stop hot water from migrating by gravity to zones that are not open. The way it is now, no matter what zone calls for a boiler start, hot water will travel by gravity into some of the other zones. It isnt always noticeable but it can overheat other zones.

nice site

I believe the point your trying to convey is that heat will migrate not gravity into the other zones.  Hot water cannot gravity without a place to go, however it will migrate no matter if your zone valves are on the supply or the return.  

I was looking at

his job specificly, It looks like an old gravity system that was either split or 3 additional zones were added, probably with baseboard or convection. On that job, sometimes not always, when there is a call for heat from any zone other than the old gravity zone, heat will migrate into the old piping because of its size and pitch. If the zone valves were on the supply it would prevent this.

Thanks again

I do appreciate the input.

Nice job

Bob I do not use zone valves but the job you did is nice, neat and it works well. Dad still likes things on the return side for the cooler water running through things. the main concern is pressure differential and the valves on the return will be fine.

My theory as to why it's working OK...

Based on the photos, I concur with others that this is a gravity conversion. Also, due ot the size of piping and the take offs coming at a 45 degree angle to the to of the pipe, any trapped or entrained air is going to get caught by the large air separators throughout the home, also known as radiators :-)

This is a bottom fill, top vented system. You can not force purge this system.

If this were a small bore pipe system, i,e, hot water base board, it would sound like Niagra Falls in the piping whenever the pump turned on. This is because the circulator has no option but to present its pressure differential as a negative pressure, which causes the oxygen that is normally in solution, to come out of solution. The greater the pressure drop/differential, the greater the potential for air noises. These big old piped systems have very little pressure differential, hence little chance of causing air t come out of suspension, and any that does is generally trapped in the upper portions of the radiators, where it wont cause much problem.

Also, there is a microbubble resorber in the mix. That will keep the dissolved oxygen at minimum levels.

As others have said, it would be a good idea to purchase Dan's book titled "Pumping Away and other neat piping tricks" and study and apply those time proven pronciples.

One of the things I have found to be true about hydronics, is that even with ALL sorts of inherent and obvious problems, most systems can still produce HEAT, but heat is but one component necessary to deliver comfort. My definition of comfort is not being aware of your surroundings. You are neither hot, nor cool, and you don't hear any background noise associated with system operation. Simply stated, you are comfortable, or you are not.

Nice pipe fitting work. Stick around here and you are guaranteed to learn SOMETHING :-0

HTH

ME

Service

Just a thought from a service standpoint. I see you have a #60 XTK in the sheet metal enclosure. #30s are heavy and awkward enough to change when filled. Double that for a 60. Maybe try adding a boiler drain underneath where the elbow is to drain it out. Much easier when empty. Otherwise a nice job