Plugged System...

Tom_133

So I got to a job yesterday because of a "low heat" call, it was piped incorrectly in every way. The customer said "its always worked good til this season" so thats 5 heating seasons with this Buderus G115 with a Beckett burner, feeding a 11/4 header with parallel piping feeding 3 zones of radiant (manual taco mix valves) and one hot loop all zones with there own pump. The spacing on the Tees was 9" apart, the circ pump was on the return almost directly on boiler. The water temp on the return never got above 130 going out of the boiler at 180.



What I found was the spirovent was so plugged with iron, and the pipes are caked 1/8th thick with orange Iron buildup. The expansion tank under the spirovent couldnt work, the pressure regulator couldnt even push water thru it.



I fixed the piping. moved the circ and replaced spirovent, now primary header flows each zone gets the same water temp. Piping is good.



Problem is the boiler with all the zones closed is taking 20 minutes to get to 150, so that makes me think the boiler is caked as well (not heat transfer). What can I do to flush this system? I have seen this before on other onyx tubing boiler jobs, is that whats causing this?

kcopp

Rohmar...

power flush the system w/ water. Add the cleaner. Let run for a couple weks. Power flush w/ water. Add the O2 inhibitor.

http://www.rhomarwater.com/products/residential-hydronic-radiant/

Tom_133

Thick goop

This stuff is really caked on, it only wants to come off when I heated the cut piece of pipe with my torch and bang it on the cement floor, then it fell off in dryed pieces. I have used system pressure to rinse, you think this o2 inhibitor will clean it? Last time I heard of it this bad the other plumber ended up bringing the boiler to a carwash so he could pressure wash it!

kcopp

well what...

other choice is there. If you drain the system totally that may get some of the junk to start to loosen up of the sides of the piping walls. Then purge the system out well. I actually hooked up a washing machine hose to street pressure water to really jack up the water pressure.

Add the cleaner and let it do its work. The inhibitor goes in only after you have cleaned and flushed the system to stop/slow the process from happening again.

Take a sample of the water when you drain it. Hot Rod has talked about a air separator that has a magnet in it that also may help.

What type of Tubing is used on the radiant?

bill_105

Beat me to it

Clean it up all you want. But where is the oxygen coming from?

SWEI

he mentioned Onix

in the original post.

Tom_133

homeowner is convinced

Its iron and not oxygen, it looks like Onix water to me though.

bill_105

Of course it's iron.

And sounds to me like iron that has taken a beating from oxygen.

Tom_133

I apologize if

there are a hundred posts on this, but how is oxygen getting into the system thru the onix?

The weak clamps, is the tubing not holding up like they say it should?

kcopp

its the tubing....

it would be the same as using non barrier pex. I have run into the same thing. Here is the nasty picts.... it shouldnt be the water because it is a closed system.

http://www.heatinghelp.com/forum-thread/140883/Anyone-seen-this