Power Flushing

timo888

I'm going to be devoting some time and $$$ to getting my relatively new high efficiency oil burner and indirect water heater shipshape. Heating oil company did not do a very thorough job and botched some things and left some components out. So I've been reading, asking questions here, trying to become an "educated consumer" .



I've read that when you get a new boiler your piping should be power-flushed to clean out any debris and limescale. Our piping (separate supply + return with branches to the individual radiators) dates from the 1940s. Should we have this service done? Is this something typically done by every HVAC company? Or is it a specialty? What does the customer look for to make sure it's being done right?

Mark Eatherton

Purging circuits...

Is different than flushing. Generally speaking, if you don't put a lot of garbage in, you don't have to take a lot of garbage out.



Now, the potable side of a heat exchanger assembly CAN be completely different, depending upon the water conditions prevailing in your area.



You MUST be able to purge the initial air out, or the system will be air bound, and will not work quietly or correctly.



Got pictures?



ME

timo888

purging the heat circuitry

We have approximately 2.5" supply and return main lines, and each radiator has a 1/2" black iron supply and 1/2" black iron return pipe connecting it to those main lines. About a dozen radiators--not the old iron behemoths about the size of large dog, but simply a length of pipe passing through a series of fins. There's a painted sheet metal cover about waist-high in front of each of the fin-rads, with a series of vertical slots at the top and an arch-shaped gap at the bottom near the floor. These sheet-metal covers protrude from the walls about 2.5 inches, but the radiators are set into a cavity in the wall about 6" deep.



As for "garbage". The article I read mentioned that after a new boiler is installed, small bits of debris from the installation itself, such as solder, should be purged from the heating circuit's pipework because it can interfere with valves and contribute to corrosion. But it also talks about "sludge".

Mark Eatherton

Good luck maintaining necessary velocity....

What you are describing is going to be virtually impossible to power purge with just city water pressure. 2-1/2" pipe is going to require a LOT of water and pressure to do a "flush".



Sounds more like a need for bottom fill, top purge situation. If you are concerned with debris floating around the system, put a Y strainer into the return to protect everything, because short of having a fire truck for a purge cart, you are not going to be able to achieve enough velocity to wash solder balls, rust chips etc. out of the system...



ME

timo888

powerflush

Yes, I understood from the article (URL cited below) that it involved specialized equipment, certainly not anything I'd have myself.



http://www.home-heating-systems-and-solutions.com/diy-heating-plumbing-tips-4.html#diy401

Mark Eatherton

Lots of misinformation there...

Maybe not mis-information as much as misguided information.



If it were me, I'd put a wye strainer in, treat the water with corrosion inhibitors and oxygen scavengers, and fill 'er up and let 'er rip.



On small bore piped systems (less than 1-1/4") the power flushing is something that is done on initial fill, but not done on a regular basis. Closed loop systems DON'T like fresh water. If everything is properly set up, you should not EVER have to re-purge or re-bleed. If the pump is in the wrong place, bleeding air is an annual event.



First indicator of problems are pumps that are mounted on the return...



ME

timo888

not on a regular basis but when new boiler is installed

A strainer on the returns that you recommend sounds like a good idea to me. But I have never seen one. Are they regularly serviced? Easy to service if so? I suppose they would be installed on the return line between the return shutoff valve and the appliance?



The article doesn't mention doing this on any regular basis -- just when you get a new boiler. And it does give some warnings--old systems might develop pinhole leaks when the rust of decades is flushed away. What especially did you find misguided?



My major concern would be valves that fail because of sludge or other junk. Is there any way to know whether the system water is "too sludgy" by taking a sample?



P.S. Our circulator pump is 6 inches downstream of the air separator, before the zone branches. We have only two zones, indirect hot water heater and all radiators. I have to bleed the radiators annually. How do you know if the air separator is working?

Mark Eatherton

No 2 systems are the same...

and there really isn't a cure all, fix all solution to any hydronic problem.



Wye strainers are relatively inexpensive, and very simple to service.



For a little extra protection from ferrous oxides (sludge) throw some magnets into the wye strainer.



I don't see the failures you are reporting of valves failing from sludge. Oh sure, I am sure it happens, but not on my watch in my tour of duty.



As for pipes failing from the inside out, the old guys will tell you that the black oxides inside of the closed loop systems are considered Black Gold, and that it should remain in the system. Not sure I necessarily agree with that position, but I think the web site you referenced is putting much more emphasis on an alleged problem, that is really not that much of a problem. Most residential systems receive NO flushing or chemical protection. Fill and go.



It sounds as if our circulator might be in the preferred place. THe arrows on the pump should have it pumping away from the air separator/expansion tank.



Easiest way to test the air separator is to put a ballon on the outlet of the auto vent, and see if it inflates.

meplumber

By chance is your system anti freezed?

I have seen the problems like that on glycol'd systems where the mix has gone acidic.

Plumberian

Powerflushing

I think that the article you were looking at refers to a process that is becoming very popular over here in the UK, where we tend to have domestic systems with much smaller pipework sizes.  e.g. most homes will have either 28mm (1") or 22mm(3/4") flow and returns with either 15mm(1/2") , 12mm (3/8") or 8mm (1/4") tails to the radiators.



You can see how it might be possible for sludge (which is basically highly oxidised rust) and/or larger bits of rust to cause blockages in pipes that small.



Although it is not compulsory in the UK (yet) to have a powerflush when installing a new condensing boiler (see    http://en.wikipedia.org/wiki/Condensing_boiler   ) all boiler makers will strongly advise that this is the best way of clearing out your system.  All gas-fired boilers have very small wareways within them and can easily get blocked.  At the moment over here, most oil fired boilers still use a large heat jacket and are not quite so fussy about the quality of the water going through them.



If I were you to be certain, I too would use a Y-strainer, but be prepared to clean it out regularly until most of the dirt has been caught.  be sure to use full-bore isolation valves either side to make that easy to do.



I would also use a magnetic filter like this one http://www.adeysolutions.co.uk/.



If you want to learn more abour powerflushing you can take a look at my sites at either



www.pritchard-heating.co.uk

www.kingofpowerflushing.com



Neither of them very pretty but they do the job.



Hope that helps and if you have any other questions I have subscribed to future posts so fire away.



All the best, Ian

timo888

just domestic water no glycol

No additives at all, just the domestic water.

timo888

where to put strainer or magnet-filter in this config

Ian, thanks for the info. Years ago I lived outside of Bath, in Charlton near Radstock, about 1/2 hour from where you are. Wish I could return! I recall drinking a beer in Norton St. Philip and you've probably had a pint or two in the very same pub.



I can see where smaller diameter pipes could get gunked up more easily. Our main supply and return lines are 2" pipes with 1/2" branches to the radiators. The returns for the back and front of the house transition to 1" iron before uniting and transitioning to 1" copper. There are valves on the 1" iron below the unions, and also a ball valve on the 1" copper close to the furnace, so I could shutoff to isolate a wye strainer or a magnet filter.



Easiest would be to intall a one-inch wye on the piece of 1" vertical copper below where the two 2" iron-pipe returns come together.



As for the magnetic filter, would the copper line have to be 90-degree ell'd so the flow would enter the magnet filter horizontally from the side? Must these filters remain in an upright orientation?

Mark Eatherton

Nice filters but...

I'm just talking about domino magnets. Something to catch any free floating ferrous oxides (rust). Pop a bypass filter/ chemical feeder into the circuit in lieu of a wye strainer, use a bag filter, and drop magnets inside.



http://www.glycolfeeder.com/SearchResults.asp?Cat=2&gclid=CMmP2u7PnqgCFQQbKgodIRyeIA



ME

timo888

inline magnetic filters

Mark, I'm learning all sorts of things from the replies to this thread. I'm a freelance software developer by trade so all of this is news to me. I never heard of a wye strainer for a hydronic system, or powerflushing, or magnetic filters, or bag filters/feeders till the past few days. But I can google like a maniac.



Following up on your mention of the bag filter/feeder and some magnets I found this earlier thread here on heating help:



http://www.heatinghelp.com/forum-thread/108832/Btu-eater



that mentions the feeder and magnets. I placed a call to the Neptune company to ask about residential feeders (they're only about 45 minutes drive from me) but they had gone home for the weekend.



I also started searching for companies in the US that make products similar to the inline magnetic gizmo that Ian supplied links for. That British company doesn't market them in the US or Canada at this time, and they told me there were no plans underway to do so. But I found this company with a similar product for the residential market:



http://www.magnom.com/

http://www.descaledirect.co.uk/boiler_buddy.htm



Magnom is a UK company too but they do have a US division, so I phoned them to see if they had any plans to bring the product to the US. They sent me some technical literature and said they'd look into the US market for this kind of product.



In their literature they describe how competing products allow trapped particles to remain exposed to the flow which can result in chunks breaking off. Their product supposedly routes the particles out of the way of the flow.

Mark Eatherton

I recognize the Fernox name...

They have been around over in England for quite some time doing boiler water treatment chemicals.



I have been using magnetic water conditioners for about 35 years, but not in closed loop applications. I typically deploy them in situations where the hardness of the water is causing issues with lime scale accumulations and decreased thermal performance,and I can state for a fact that they DO work. I can't tell you how (lots of differing theories) but bottom line, they DO work. But in a closed loop application, if you have lime scale accumulations occurring, it is an indication that you have a leak in your system with continuous fresh water makeup occurring. And if in fact you do have a leak in your heating system, you'd best locate it and eliminate it or your whole heating system is going to go away.



Quite honestly, all of this "Power Flushing" looks like a marketing angle by Fernox, who is in the hydronic fluid treatment business to sell product. Granted, the Euros have MUCH more hydronic experience than us Colonizers, but if it were TRULY an "issue", our industry would be aware of it and would be on it like white on bread.



Unless you are actually experiencing any kind of comfort issues with your heating system, I'd recommend that you hang on to your hard earned money, and use it for things that would be of definite known benefits, like additional insulation, storm windows, boiler tune ups etc.



Leave it to the Brits to come up with something to make money on something as obscure as power flushing a system that doesn't really need it. Now, if they can show proof of significantly increased performance, I'd buy into it, but my brief scan of their literature didn't support that.



Freelance programmer eh... Do you have any experience writing Boolean logic for programmable logic controllers? I'm looking for someone who can help me in this arena.



ME

timo888

system problems

On programming: what control language do your devices use?



Here are the symptoms that make me think our system may have a problem:



Our radiators have suspended bits of grimy waxy black crud in the water. These little bits can be smeared and make a black streak. Some of the radiators need to be bled more than once a year. Others spit 100% water only, no air, when the valve is opened.



We've had a Taco pump fail after two years and apparently a feed valve has gone bad now too. When the feed valve is not isolated, pressure on the gauge goes up to above 40psi. When the supply-side ball valve immediately before the feed valve is closed, the pressure on the gauge does not exceed 32psi.



There's an encrustation like limescale on the tip of the SpiroVent air separator (see pic). I am not sure the SpiroVent is working any longer. Our water test results came back recently as "moderately hard". Maybe this is normal--I've only seen this one unit in my entire lifetime and have no frame of reference. I realize it's a closed system, but if there's a leak or leaks, and fresh water is coming into the system on a regular basis, then maybe the SpiroVent's tip is like the beak of the canary in the mineshaft.



I don't know if these symptoms amount to a system leak , or if the valves have failed because of suspended iron and/or high mineral content in the water. But if something passive and non-invasive like the magnetic filters for the iron particles and some other sort of filter for minerals were not too expensive for me (three numbers to the left of the decimal point, not four), then I'd probably spend my money.



But after reading that powerflushing could make matters worse by opening pinhole leaks in old systems, and reading that flushing 8 radiators can take all day, I would probably not have that done, unless those pinhole leaks could be easily fixed by pumping something into the pipes -- like the green slime you can inject into bicycle tires through the valve to repair flats-- and the HVAC company were running a special: "Sign up with us for a 5- year maintenance/emergency service contract and get a free system powerflush!"

Mark Eatherton

George Boole's baby...

Boolean logic is a machine logic used in most programmable logic controllers.



Re: Your problems, the little bit of corrosion showing on the tip of the auto vent looks normal to me.



The black stuff you are seeing is normal oxidation. It can be suppressed with the use of anti oxidant and oxygen scavenger chemicals, but it creates an ongoing requirement of maintenance. A fact of life is that most people don't fix what doesn't appear to be broken. you are obviously an exception to the rule.



Air, and oxygen has a tendency to accumulate where the flow is the lowest, the water is the hottest and the pressure is the least. If you are getting air in upper floor radiators, it is to be expected.



The circulator failure MIGHT be associated with the heavy oxides in the water, but may not. The failed pressure reducing valve has nothing to do with the oxides in the water.

THe pressure reducing valve only "sees" fresh water. They fail on their own, usually from a lack of use.



Most residential boilers are equipped with either a 30 or 45 PSI relief valve. What is the setting of yours?



If you keep the make up water off, and the pressure doesn't drop to zero, then you probably don't have a leak.



ME

timo888

what doesn't appear to be broken?

Mark,

There's water on the floor below the pressure relief valve.

The feed valve appears to be failing (enabled, baseline pressure is 22psi; closed off, baseline pressure drops to 12psi).

A Taco circulator failed after 2 years.

My radiators need to be bled often.



Certainly not looking to create problems for myself. But if it looks like it's breaking, find out what's going on and eliminate the problem.



Thanks for the judgment on the Air Separator tip and the warning about continual maintenance if anti-oxidizers are used. Helpful warning.



I know what boolean logic is. However, to talk to the controller board about things like delays of varying duration and maximum/minimum threshold temperature or pressure values takes more than the boolean logic per se. The manufacturer provides some sort of device programming interface to allow the programmer to create rules that involve timers and specific value settings. Sometimes those programs are written in the C programming langauge. Sometimes the manufacturer will "shield" the programmer from low-level programming-language syntax difficulties by providing visual toolkits in lieu of a language--or together with a language or languages--so the devices can be programmed by dragging symbols or pictures on the screen. For example:



http://www.deltacontrols.com/solutions-products/products/software/orcaview

Jean-David Beyer

continual maintenance if anti-oxidizers are used

My friends who operate steam locomotives do put water treatment in the water in the tender that feeds the boiler. The steam generated in the boiler ultimately is blown out the smokestack, so the add water every few minutes of operation. They also blow down the boiler on a regular basis because of all of the "mud" that settles to the bottom of the boiler after a while, and because the contration of some of the components of the water treatment need to be removed. Sodium sulfite, for example, turns to sodium sulfate as it absorbs oxygen.



I do not recall just what is in their water treatment, but some of the ingredients are sodium sulfite (oxygen scavenger), sodium hydroxide (neutralizes acids), oxalic acid (I do not know what it is for). They test the boiler water before they put this in and vary the composition depending on how the boiler water tests out. Their boilers have more extreme "leaks" than even a steam boiler for home heating would have. All their piping is steel, not copper. Their boilers are firetube boilers, and they do not want those firetubes to rust, or to get mineral deposits on the water side because if they do, the tubes overheat and must be replaced. The water they use happens to have a lot of iron in it and I hate the taste of it, but they do not have much choice. I do not know if the iron is a problem for them or not.

timo888

closed system water quality

Thanks, JDB, about the water-testing example.



It seems the old-timers view that Mark mentioned, namely that the iron oxides are "black-gold", runs counter to the view that they can cause valves to fail. But I would rather replace a valve than have to track down and repair pinhole leaks.



One thing everyone can agree on is that fresh water coming into the system on a regular basis is not good for longevity. The main thing for me is to eliminate the overpressure situation which is causing new water to come into the system on a regular basis



It seems to be the feed valve, so I'm going to have a new feed valve installed. May also put a Honeywell Supervent air separator on and leave the original SpiroVent in place. It couldn't hurt to have two devices getting rid of oxygen.

Mark Eatherton

So, you do have a leak....

Not a hidden leak per se, but you DO have a leak, and no leak is a good leak.



As I stated previously, the failure of the reducing valve is not related to your BOILER water quality. I never leave an unsupervised solid connection to a make up water system. But I can't recommend that you shut off your make up water unless there is a functioning low water cut off in the safety circuit.



You may also have a bad expansion tank, stuck bladder in the tank or the tank may be borderline undersized.



The most I'd recommend be done is to install either the wye strainer or pot feeder/filter. use a Rhomar to clean up the system, and Rhomar chemicals for corrosion inhibition.



The pH of your system should hover around 8.5 but not less than 7.5 nor more than 9. If it is significantly different than that you could be generating hydrogen gas, which you are seeing as an "air" problem in certain radiators.



If you want to avoid the issues of pump lock up, don't use a water lubricated circulator. Taco and Bell and Gossett both make a 3 piece circulator that requires manual oiling (monthly during the heating season) that are bullet proof as it pertains to ferrous oxides in solution.



There is an assembler program for these PC/PLC's, but I have it on another machine, and the name escapes me right now. Let's get your problem under control before we wander off into the weeds with mine :-)



I have, in rare cases, installed a cartridge filter assembly in parallel across the system to filter out excess oxides. You have to make sure that the filter assembly is compatible with the temperatures and pressures you would be seeing in the closed loop system.



ME

timo888

relationship of feed valve to system pressure and system water quality

"The pH of your system should hover around 8.5 but not less than 7.5 nor more than 9. If it is significantly different than that you could be generating hydrogen gas, which you are seeing as an "air" problem in certain radiators."



Here's my thinking ...A failing feed valve could affect system pressure. If the pressure is too high (as mine seems to be when the feed valve is left OPEN), the overpressure valve releases water regularly--whenever the unit fires for more than 20 minutes the pressure gauge exceeds 40psi. When water is released by the OPV, new fresh water is entering the system again via the feed if it's left open. And so indirectly the water quality does change, including its pH, on account of the feed valve issues.



I had our domestic water tested a few weeks ago.

Moderately hard (total as CaCO3): 92

pH of 7.04.



So we're injecting 7.04 pH fresh water regularly and that is lowering the system pH. I haven't measured the pH of the system water, though, but can do that.



After getting your reply about hydrogen I found this here:

http://www.heatinghelp.com/forum-thread/99934/Flammable-gas-in-hydronic-heating-system



When I was working on my bathroom remodel last summer, I happened to grab with wet hands the capped black iron supply pipe and the capped black iron return pipe for a removed radiator that was going to be replaced with a towel radiator. That gave me quite a tingle -- not a really bad shock but enough to make me want to let go pronto. So I believe we may have a stray current. After that I yoked the two pipes with some bronze clamps and a 10-gauge copper wire. I asked an electrician if the pipes were hot and he tested and said nothing he could detect.



"But I can't recommend that you shut off your make up water unless there is a >> functioning low water cut off in the safety circuit."



Roger that. LWCO is on my to-do list.



"You may also have a bad expansion tank, stuck bladder in the tank or the tank may be borderline undersized."



I accept this as a possibility but the system pressure seems to have stabilized ever since I closed the feed valve, and the bicycle pump gauge showed 12psi when attached to the Extrol.



"The most I'd recommend be done is to install either the wye strainer or pot feeder/filter."



I'm on board with the wye strainer. The pot feeders with filter bags that Neptune has are way too big, and costly, I think--unless there are smaller ones more suitable for residential systems?



".. use a Rhomar to clean up the system, and Rhomar chemicals for corrosion inhibition."



I will read up on the Rhomars. Name is new to me.



"Taco and Bell and Gossett both make a 3 piece circulator that requires manual oiling (monthly during the heating season) that are bullet proof as it pertains to ferrous oxides in solution."



Thanks for the info. I will look into it.

Plumberian

Power flushing

Blimey Tim,



small world eh?  Next time you are nearby let me know.  There are many  more pubs around serving decent beer now and it would be a pleasure to buy you a few pints.



Re. Magnaclean,



It is best installed upright, but can be installed at an angle. Ideally no more than 40 degrees from vertical.  Any closer to the horizontal and you might have initial problems with air locks within the the housing.



I had not heard about Magnom filters so thank you for the info.





Mark, you are cheeky bugger but it is good to hear from someone as experienced as you.



As far as I have heard, the original company that started selling 'powerflushing' chemicals and equipment to pump their chemicals around heating systems was Kamco (www.kamco.co.uk).  These guys were the first ones that started to recognise the problem of corrosion-caused blockages in domestic systems as a serious problem.  In the UK they are a serious problem. Your heating pipework tends to be a lot bigger diameter than our domestic systems and will not block up so easily as ours.



Historically your energy costs are way lower than ours.  For example, large amounts of water take more energy to heat up.  Currently I am paying between £6.28 and £6.75 per gallon for diesel fuel. Perhaps that is why your manufacturers have not taken energy saving to heart.  Just a thought.



Best wishes



Ian Pritchard

Mark Eatherton

I hear you Ian...

Cheeky Bugger indeed ... I've been called worse :-)



The only partial close off of tubing that I am aware of is in radiant floor heating system using rubber hoses. I have a friend who went to ISH and came back with a flushing device specifically attempting to address those conditions. Most of our distribution piping is 1/2" and larger, with an occasional 3/8" tube. Our mechanics also have a tendency oversize their pumps, so sludge doesn't really have much chance to come out of suspension.



Most of our systems are also a closed loop system, so the ingression of oxygen is minimal. I had an Englishman that use to work for me, and he said most older systems he'd worked on in England had an open "cylinder" in the attic, which creates an open path for oxygen ingression.



There are some older (1890 to 1910) systems that used an open tank in the attic for gravity, but for the most part, our systems are truly closed loop.



Thanks for sharing your wealth of information on Olde English systems. Your country has been at this hydronics stuff for much longer than us Yanks.



ME



ME

timo888

we're slowly catching up to those prices

Ian,

I miss that real British beer...and the hard cider...and shove ha'penny. I'll have to dream up some plan to visit England -- maybe a blog about the latest advances in British residential hydronic heating technology, and Magnom will send me over to tour the factory.

Rich Davis_2

While We Are Discussing It

Hi All,

   I'll be putting water to my new system in the next couple weeks.  I used a lot of re-cycled components ie baseboard convecters and 3/4" pipe.  Should I add somekind of cleaner during the inital flush.  There is also a lot of shavings in the pipes from deburring.  I've installed a Spiro-trap, which I'm hoping will take care of the loose stuff in the system that the flush misses.  Also how would I add a cleaner?  Thanks ahead of time.