please help bad water hammer new install

eldwin

Hello guys ,New to foroum but need help bad, and seemes you are quite knowlageable, i recently had a install done. i had a 70 year old national steam gas boiler 435,000 btu replaced , the installer seemed verry knowlageable at the time i atempted due dillagance and did a quite a bit of research but the qualfied list seemes to be verry short i definatly recived the impression that it is not so much the equipment now adays as the installer , i still trust the installer but am now looking at some charges for him comming back for a problem that didnt exisist before the install and we are verry tight on funds here , the solution was to install 2 slant finn boilers one as a slave with a delay in essence creating a two stage boiler both piped together,the main is a 275.00 btu, slave is a 200,000 btu that will kick in at 12 minutes if main dosent sastify heat call,, the piping alone is creative but verry clean and professional and yes we now have a hartford loop the water feeder is on the slave side and both LWCO ard sending signal to feeder he may want to use only one..? not to keen on that .., the problem is the main boiler semes to be calling for water turing on and off and then overfilling , while feeder on lowest setting , durring morning fire up from 63 to 66 i am getting aloot of watter hammer BAD, installer stating to much lag in return for condsate comming back , wants to try chemicals to free up rust in return and run a pipe snake in old pipereturn to free up if blockages...? snake could crack pipe right? 119 yr old buliding...?right? aslo sugested second resivoior by furnace cant rember termanoligy but seems what ive read it cant take pressure and has to vent seperatley ... new concerins with that include brick errosion? need stainless flue? please help

EBEBRATT-Ed

pictures

Gotta have pictures to help you. Two steam boilers in parallel can be done but it is not a simple install. Is this gravity return or do you have a condensate pump or boiler feed system...........I am guessing gravity.

problems:

The idle boiler will fill up with condensate and will act as a condenser for the steam in the system.

When the boilers are both operating even if the pressure is different by ounces the lower pressure or idle boiler will get the condensate leaving the operating boiler to trip on low water cutoff.

You probably need a boiler feed system with two pumps to make this system work.



Spilt milk but you probably would have been better off dollar wise with 1 boiler and a burner with L-H-L operation.



Just saw the pictures. Please tell me the gage glasses for the water level are at the same height.

eldwin

reply

negative the slave is maxed out and the main one wich is the first in the picture and shorter one is almost maxed out, i have the feeder on the lowest setting, and the installer wants to charge me to fix , he convinced me to do 2 instead of one siting future repair cheaper and easier to swap and also that it would operate more like a 2 stage forced air cheaper heating bills , he seemed the most knowlageable out of all the quotes he even added a milivilot system to the first unit if we lose power thats why you see the old style lwco in the pic the 2 new units have probe type, i have more detailed pics but wont load i can email if you like and tahnk you so mush i am hurting over here it is cold and the walls are banging

EBEBRATT-Ed

Help

Wish I could help but with all due respect I don't think your installer has a clue. The boilers have to be the same height as far as the water line is concerned unless you install feed pumps. the alternative is to raise the lower boiler.

Get the manufacturers piping instructions as a start. I don't know what to say except I think you have a lot of issues.

JStar

Boilers

Let's get some pictures of the supply piping, especially how the two boilers tie together.

nicholas bonham-carter

tag team boilers

I suggest you control the second boiler by pressure, with a vaporstat. when there is a call for heat from the thermostat, the pressure will be zero, and both boilers will fire. At a few ounces, the vaporstat will then cut the lag boiler off leaving the larger lead to continue steaming. a time delay will be an iffy proposition, as the timing of the lag boiler will be different for a design degree day from a merely chilly day.

so where is the water going? get set up with a good book, and start skimming the oils out of the whole system. check to make sure all the wet returns are well below the new lower waterline on those boilers. keep the pressure low, and make sure the risers are sized right so as not to squirt everything up into the supplies.

you can try doing a little snaking out of the returns. if the pipe breaks, then at least you are there to deal with it, if it is that delicate.--NBC

eldwin

reply

trying to up load now , to answer previous , the boilers are level just the shorter one / master is manufactured shorter and stouter the pipe that joins them in the middle is level only slightly pitched mabyee a heavy1/16 off they are slant finn galaxy steam boilers one is 275,00 other is 200,00, yes it is gravity feed, i will blow down and at rest the two water levels are even , starting off the problem arises when it heats up and lwco turns off and calls for water it will over fill due to the calling and the condsate taking too long to get back once it gets back and this hapens for 5 or10 heating cycls they both will be maxed out or the slave over full due tto i asume return comming to it first and the master just below the top of glass, resulting in me having to skim /drain once a week to reset levels , from wjat i have read so far this semes to be a somewhat commen problem on new installs, i.e. newer ones holding less water , this is what my installer says,

Jamie Hall

Multiple boiler setups

are perfectly feasible.  They are not a bit simple.



They can be done with gravity feeds, however it is absolutely essential that the design water lines of the boilers be the same.  Further -- and perhaps more important -- it is essential that the headers and equalizers be fully interconnected; part of the problem you are seeing may be that the non-firing boiler may not be seeing the same steam pressure and main pressures as the firing boiler.  If this is the case, the water will back out of the firing boiler into the non-firing boiler and you will have problems.



I definitely agree with NBC -- control the boilers with pressure, not timers.  Use vapourstats and make sure they are both very carefully calibrated.  In my view, they should be on the same tap off the header -- not off the boilers -- and have snubbers.

eldwin

reply

thank you jamie annd nick i will let him know , i do trust his install just want it to run right and i also dont want to be that customer lol !! but i am also a blue collar guy who is in skilled trades and am inqusitive and also broke lol i just cant afford call outs if not due to blding and not install but understand you get what you pay for wich is y i went with him, i am trying to up load pics but they are not working right i can text or email them just email me and i will send detail photos should i do his idea and tsp in system and snake? will it fix? and also thank other forum poster did you get photos?

nicholas bonham-carter

Boiler sizing

Keep trying to post more pictures of the piping. The piping of this pair is the key to whether it works or not, and at the moment it seems to be a problem. Click on Jstar's avatar, and look for his details of a 2and 3 boiler setup. You will see the only way the piping can be made to work.

How was the total boiler sizing chosen? The system must be pretty big for such a pair-maybe 20 radiators? Is this 1-pipe or 2-pipe?--NBC

nicholas bonham-carter

Hope we can see the completed system

We like tandem boiler setups!!--NBC

ALIGA

this maybe too late

how did the installer come up with the replacement size of 475K BTU?



did he just upsize the old boiler?