Water Hammer After New Furnace Installed

Sleepless_in_NY

<span style="font-size:12pt">My husband and I recently moved to a new apartment in a 2 family house. We rent the top floor of the house and there are tenants on the first floor. A few weeks ago a new furnace was installed in the basement. Since its installation, when the heat kicks on there has been a water hammer problem that lasts anywhere from 30 min to an hour - most notably in the middle of the night when the heat kicks on. From what we can tell, it seems this is happening beneath our bathroom and bedroom radiators. The tenants downstairs are also experiencing the water hammer problem. </span>



<span style="font-size:12pt">The plumber who installed the furnace said that the thermostat has to be set no higher than 68 and that the water hammer problem will continue if the thermostat is set above 68. Everything we have read says absolutely nothing about what temperature the thermostat is set on as being the source of the water hammer problem.  The plumber also told us that this problem is not fixable and that it's normal, which I find unacceptable. Can you please give me some advice on what needs to be done to fix the water hammer problem, and also if the thermostat being set above a certain temp would cause the problem.</span>

<span style="font-size:12pt">Thanks!!</span>

BobC

Thermostat has nothing to do with it.

A properly sized and installed steam boiler works no matter what the thermostat is set to, if it's a bit small it might not be able to put out all the heat you want but IT SHOULD NOT CAUSE WATER HAMMER.



Has the installer been back to skim the boiler to get the boiler water clean? It sounds like he may not know steam all that well, there are not a lot of qualified steam men and this sounds like someone that got in over their head.



Post some pictures of the boiler and the piping that comes and goes from the boiler so we can see what he did.



Bob

Sleepless_in_NY

Just as suspected

Just as we suspected Bob! We will take some pics when we get home from work later today and post them. I'm with you - I think this guy is flying by the seat of his pants.

I'll be in touch!

Jamie Hall

Hopefully...

it's just that the new boiler needs to be skimmed.  That's easy (provided one knows how to do it, of course).



But.... one has to be a little suspicious; if it started after a new install... that maybe the new install wasn't quite up to par as to near boiler piping... so send us some pics as BobC says, and we'll take a look.

STEAM DOCTOR

Pulling your leg

I work in Queens and see steam systems by the zillions. Never is there a correlation between high thermostat settings and water hammer.I see people with thermostats set to 74 with no water hammer and I see people with thermostats on 65 that have water hammer like crazy. Water hammer in NOT normal and is always a sign that something is wrong. Try to find out if there was a water hammer issue with the old boiler. If there wasn't then obviously the water hammer is related to the new boiler installation. Try to post pictures o the boiler and surrounding piping from different angles.

Rod

Pictures will be a big help.

Hi- When you take pictures of the boiler take them farther back from the boiler so we can see the boiler and the piping connected to it. This will allow us to trace the piping so we can see if it was configured properly. If possible include pictures taken from different sides of the boiler. We can blow up the pictures if we need to see more detail. Also look on the boiler as there should be a name plate which shows the boiler manufacturer's name and boiler's model number. Having that information maybe of help too.

     Steam systems are classified by the number of pipes connected to the radiators. If one pipe is connected to a radiator, the system is called  a "one pipe system". If two pipes are connected to each radiator it is a "two pipe system".   When you look at your radiators, how many pipes are connected to each radiator??

- Rod

SleeplessInNY

Pictures

Hey guys,

Here are some pics. There was no water hammer occurring prior to the installation of the boiler. The radiators have a single pipe into each one, so I guess a single pipe system. Hope these pics help!

Thanks!

STEAM DOCTOR

water level

Watch the water level while the boiler is firing. If the water moves up and down a lot then the water probably has dirt and oil in it and needs to be properly cleaned and skimmed. Also the water level should be approx halfway to 2/3 of the way up the glass.Just noticed that there is a reducer in the header. What is the make of the boiler?

Steamhead

It's a Williamson

same as a Weil-McLain EG. Model GSA-150.



That equalizer looks awfully small. And the header was reduced, looks like 3" down to 2". This could be part of the issue- the header is supposed to be 2-1/2". And there's no Hartford Loop.



The piping diagram is here:



http://www.williamson-thermoflo.com/en/multimedia-library/pdf/williamson-pdf/w-gas-steam-atmospheric/550-110-738_0210.pdf

Rod

Boiler Piping Problems

Hi - I started out writing a reply and I see Steamhead, who is a very experienced steam pro, has already posted an answer outlining the problems with your boiler. The installer obviously didn't follow the boiler manufacturer's piping instructions.  As Steamhead mentioned, it looks like the Header and Equalizer are undersized and there is NO Hartford loop.It is very important to the proper (and silent) operation of the boiler that it is piped properly.

 I've attached one of your pictures with labels and also the piping diagram and pipe size specification table from Page 11 in the GSA installation manual  available on the link which Steamhead posted for you.

- Rod

STEAM DOCTOR

Return

How high is that horizontal copper pipe on the far left of the boiler.Its hard to tell from the pictures but if that pipe(known as a wet return) is higher then it should be then that could cause hammer problems(referred to as A dimension problems). Measure the height of that pipe from the floor and measure the height of the middle of the water level glass from the floor.

SleeplessInNY

Hartford Loop

Hey guys, the husband here. Had my wife post this yesterday as my job doesn't allow me to do anything but work related when I'm there.  Thanks for your responses and help. You'll have to forgive me as I know absolutely nothing about heating, but am being forced to learn as I want to be prepared on what questions to ask and what to look for because we are now going to have to be the ones to find a reputable person to look at/fix this as I just don't feel comfortable/safe having the person who installed this come out for a 4th time. I wanted to ask about the Hartford Loop. In the boiler manual(page 11) it shows 2 diagrams. One for counterflow steam piping(which it looks like he used) and one for parallel(which you guys are saying should have been done).  Any reason other than pure laziness as to why he might have installed it this way? I don't fully understand the Hartford Loop(yet), but from what I've been reading it sounds pretty important. Anyway, thank you guys for looking at those pics. I'm off to see if I can get a reputable/qualified person over here to fix this problem.

Abracadabra

Re: Water Hammer After New Furnace Installed

I think you've got counterflow and parallel mixed up.







Counterflow and parallel refer to the way the steam and condensate in the house piping run.

Counterflow = the condensate runs counterflow (backwards) to the direction the steam takes.

Parallel = the condensate runs parallel (with) the direction the steam takes.



I don't think we know if your house piping is counterflow or parallel. Unless I missed something in the thread.





With regards to the hammer, Check the level on any return pipes that were changed (or possibly moved) and make sure that they have some pitch so that water doesn't sit in those pipes.  I had a boiler where the installer didn't want to repipe a return to the boiler, so he just crowbared that pipe up a couple of inches to connect it to the boiler.  Those couple inches cause a "bend" in the pipe that allowed water to sit there and cool after the boiler finished it's cycle.  When the boiler started up the next cycle, the hot steam would hit the cold water and "BANG".

STEAM DOCTOR

pitch

When the returns are wet returns(meaning that the returns are below the boiler water level) then pitch does not matter. All wet returns have water sitting in them 24/7. If the returns are above the water level(dry return) then pitch is critical.

Rod

Parallel and Counterflow Steam Mains

Hi- The two diagrams on Page 11 in the manual show how to pipe the boiler for two different steam main configurations - One called “parallel flow” and the other called “counterflow”.

In a Parallel Flow Steam Main, the end of the steam closest to the boiler is higher than the end of that steam main farthest from the boiler. This means that the condensate (water) returning from the radiators, flows away from the boiler ( there’s a pipe connected to the far end of the steam main which then returns the condensate to the boiler) Since the steam going to the radiators and the condensate returning form the radiators, flow the same direction in the steam main, this is know as a “Parallel Steam Main” or a “Parallel System”.

On a Counterflow Steam Main - The end of the steam main closest to the boiler is lower than the farthest end of that steam main away from the boiler. This means the condensate (water) flowing from the radiators flow down the steam pipe back to the boiler. Since this is in the opposite direction of the steam going to the radiators it is known as a “Counterflow Steam Main” or a “Counterflow System”.  In a Counterflow main there is a tendency for the steam flowing up the main and condensate (water) flowing down the main to collide which reduces the efficiency of the system. From looking at your pictures I believe you have a parallel steam system .However you might want to check your mains for comparable height just to make sure. I’ve attached a couple of diagrams of typical piping of parallel and counterflow systems.



Books- I would highly recommend you get a book that is available in the Shop section of this website. It’s called “We Got Steam Heat!”. It’s written for the homeowner new to steam heating and is easy, humorous reading. It’s filled full of diagrams and pictures which in a few evenings of reading will put you “light years” ahead in your knowledge of steam heating systems. One of the biggest advantages is that it quickly gives you enough knowledge to know if the heating person you are talking to really knows and understands steam heating. Here;s a link to the book:

http://www.heatinghelp.com/products/Steam-Heating-Books/25/61/We-Got-Steam-Heat-A-Homeowners-Guide-to-Peaceful-Coexistence



Links of interest.

Hartford Loops-

http://www.heatinghelp.com/article/325/Piping/291/What-you-should-know-about-Hartford-Loops

Boiling Piping Video -

http://www.heatinghelp.com/article/107/Steam-Heating/118/Steam-boiler-near-boiler-piping

A Steam Heating Primer-

http://www.heatinghelp.com/article/321/Steam-Heating-Basics/128/A-Steam-Heating-Primer



Unfortunately there are a lot of heating people who really don’t understand steam heating and seem to think that all one has to do is connect “A” to “B”.  Residential steam heating is actually quite simple. It’s just that you have to know and understand the basic rules for steam and while knowing the rules is obviously makes one more competent, in actually all you really need to do is just follow the boiler the manufacturer’s installation instructions. If the installer had just done this you wouldn’t be having the problems you are having now.

- Rod

LHthread

Uh Oh!

Not a good size of the eqalizer or the Hartford loop tie in.

1" copper ?? Not good. I think by now you would have called back the installer?

Tell the installer to Open the Installation manual in reference to piping.

SleeplessInNY

Had someone else look at it

Let me say that it was our landlords which used the fellow who installed this boiler. He has already been out 3 times to look at it since installation. Not wanting to have this guy out a 4th time and feed us a load of crap, I asked if we could get another set of qualified eyes on this. Another gentleman came out yesterday and agreed..needs a Hartford loop, & also said installer should not have used copper piping. Also, wet return is too high. He seemed like he knew what he was talking about, and answered all my questions and concerns and even looked at all the radiators upstairs and pointed out issues. I've gotta get back to the landlord today to give him the price for a re-installation. Again, thank you all so much for your help, I've learned so much from these posts. I'll send pics of the re-installation when it's completed.

BobC

Good

I'm glad you got someone else to look at that installation. Copper is ok below the waterline but not above it. Having the wet returns connect above the waterline is not good, it almost guarantees water hammer. Between properly sizing the equalizer and correcting the tie in of the two returns he should be able to quiet things down. After that work the boiler will need skimming to remove all the contaminants from the boiler water. 



Putting in a harford loop is good insurance against dry firing in case of a return leak.



Bob

Rod

Skim Tap

Hi- Glad you were able to find someone to straighten out the boiler piping. Properly done this will make the system silent, comfortable and more fuel efficient.

Skimming- Be sure to have the guy reconfiguring your boiler installs either a long pipe nipple and a cap or a setup like that shown in the attached picture so that the boiler can be properly skimmed.  If you look in the Installation manual on Page 7. In Figure # 3 and in Table # 4 you will see that the boiler port marked “S” is for the skim tapping. Here is a link to a post which contains some info on skimming:

http://www.heatinghelp.com/forum-thread/138635/Need-help-Putting-off-skimmg



As Bob mentioned you can use copper bellow the waterline for the wet return. Copper shouldn’t be used for piping that contains steam.

Since the competency of the other installer seemed questionable, you might also have the new guy check that your main vents are working properly and are of the right size capacity.

- Rod

Abracadabra

copper & steam?

What's wrong with copper for steam? I have a radiator hooked up with copper for steam and it's been working fine for the past 7-8 years. 

Jamie Hall

Copper and steam

The trouble is expansion and rigid joints.  I too have radiators -- two -- which got piped with copper many years ago, and they still are fine.  However, a radiator -- piped with let's say half inch or three quarter inch -- is one thing.  A header, piped in two and a half or three inch, is quite another.  The latter is much more rigid.



In principle, it is possible to arrange a header or steam main so that the expansion is taken up entirely in bending the pipe, and not in putting torque on the joints.  In practice, this can be difficult.  Further, if you want to take it up in bending, the distances have to be rather long to keep the stress within reason.



This is not to say that a copper header, soldered together by someone who really knows their trade and gets really good solder joints (itself not so simple on big pipe) won't work.  It will.  It will put an enormous strain on the boiler, if you have two or more risers and they aren't properly piped to eliminate expansion forces, but it can be done.



But it's a lot easier to do it with iron pipe and threaded joints...

jpf321

too high?

Sorry, I typed something earlier .. but now I know that you meant that you need all your wet returns to always be wet .. and that if a wet return is dry, this will cause problems.



But with regards to the A Dimension, you can never have that be too high. But you can have wet returns which are too high (not beneath the waterline).

STEAM DOCTOR

dimension A

The dimension A can never be too high. What could happen though is that a return that should be lower then the water line (and hence a wet return), will instead be above the water line and as a result the A dimension will be much shorter then it should be because the old wet return has now been turned into a steam carrying pipe. I don't have my copy of Lost Art in front of me but I'm fairly certain that Dan makes mention of such a thing happening.

jpf321

we are on same page ...

you responded to my pre-editted post. i editted it again prior to your response. basically when installing a new boiler .. make sure that all pipes that you expect to be WET remain wet after any possible waterline changes.

rcrit

mine leaked

As someone who had a copper header I can say that mine leaked at a joint. It was very small but every cycle I lost a small amount of steam. Every week when I blew down the boiler I'd have to add a little extra water to make up for this loss.



When my boiler was replaced this was replaced with a proper header (both in design and material).