Superfluous Hartford Loop?

2wheelinfool

I read about the functions of the Hartford Loop here, and got to thinking about my system. Isn't my Hartford Loop superfluous since I don't have a significant horizontal run of wet return line? What's it doing in my configuration?

JUGHNE

One benefit is it is a sludge settling point. Keeps junk out of your boiler if you drain the bit of wet return you have there every year. Drain hose on the bib and you can back flush a little by manual water fill valve to loosen any solids.

Do you have another drain on the other side of the boiler to actually drain it to the bottom?

2wheelinfool

Thanks, @JUGHNE . I want the hose going to the red-handled valve, and flush out through the yellow handled valve, right? Once a year good?

pecmsg

That works.

For safety's sake install a plug in that valve when done!

EdTheHeaterMan

That would force any sludge into the boiler. I would think that you don't want that. I believe the process is to open the drain valve at the bottom of the Hartford loop. If nothing comes out, or it does not come out with normal force, you backflush with a few ounces of water to break up the sludge. In-out-in-out like a plunger. Just takes longer because you need to connect and disconnect the hose to change the flow direction.

If you do it annually then there will be very little sludge to flush and you will not need to break up any blockage.

Yours Truly,
Mr.Ed

2wheelinfool

@EdTheHeaterMan, doesn't the boiler itself develop sludge due to it's own corrosion process? What it still be inadvisable if I first cleared the Hartford loop, and then cross-flushed the boiler? How do you flush the boiler?

EdTheHeaterMan

2wheelinfool said:

How do you flush the boiler?

Open the yellow handle valve.

2wheelinfool said:

What Would it still be inadvisable if I first cleared the Hartford loop, and then cross-flushed the boiler?

Yes

2wheelinfool said:

Doesn't the boiler itself develop sludge due to it's own corrosion process?

Yes


Weekly is too ofter. Annually is recommended.
Weekly flushing is for float type LWCO. ...And if your boiler is for space heating your home, depending on the size of the system monthly or every other week could be OK. Depends on how much junk comes out weekly if you can skip a week or not. If it were my home, I would flush weekly until the water runs clear. That should be about 1/2 of a 3.5-gallon pail.

JUGHNE

If you put a drain hose on the red valve and drain out the "U" shape of the piping at the HL, hopefully it drains out fairly well.
Then close the red valve and open the manual water fill valve (green handle) up above to the right of the auto fill device. Open and close a few seconds at a time. Like Ed said, sort of chase the junk back and forth. Then leave green closed....open the red valve and see if you get more sludge out of it.
Repeat until pretty clean drain out.
You do not want to flush the sludge into the boiler only back flush things loose in the "U".
You can watch the sight glass level so as not to wash into the boiler.

Then move the drain hose to the other side (yellow handle) you need a 3/4" pipe male by male hose adaptor with 2 brass caps, and drain the boiler, flush again with the green handle fill valve.
You use the green handle to supply water for both of these flushes.
Watch the sight glass level as you flush, be sure the hoses are draining.
Do not fill above the top of the sight glass as you do this.
When things seem clean enough, fill to the center of the sight glass and fire the boiler up to boil off any oxygen gained by fresh water introduction.
Put the hose fitting cap on the drains.

IIWM, I would flush only the HL "U" every year and the full flush 2-3 years.