HEAVY crud found on newer Weil-McLain CGa-4 overhaul

Cherny

For everybody that helped me with the previous post, thank you so much! Shortly after performing pretty extensive maintenance and getting the system working adequately, we had a couple of leaks on the Poly-B supply/return lines (one of them under our foundation) from the boiler and decided to bite the bullet and re-pipe the whole house with PEX.

The boiler is a 6 year old Weil-McLain CGa-4.

I have now completed the re-pipe and I'm in the process of re-building the boiler room. During disassembly of the near boiler piping I came across A LOT of sediment in some of the copper pipes (see photos). As you can see in one of the pictures, the sediment is pretty heavy on the supply coming out of the boiler too. I'd like to inquire from the wealth of experience folks have on here on the best way to clean the boiler before re-assembly. Right now I only have the front panel off the boiler but I'm not opposed to completely disassembling if it will give me access to the guts for a better cleaning. Is there any tools folks use that I can shove down the supply/return pipes to move most of the sediment?

I did have HydroSolv 9100 cleaner running in the boiler for about a week before we had the leaks and shut it all down.


The sediment appears to be extremely fine rust particles that congeal together into an almost paste. It is easily scraped off with a finger swipe.

Thank you everybody!

hot_rod

You need to get a good flow through that boiler to flush it out. The sooner the better. The Rhomar cleaner has softened the gunk. It will turn into a hard deposit if you let it dry and become almost impossible to get out. Like red cement!
It is called hematite, the ferrous metals that have broken down from the O2 ingress with the PB tube.
Connecting a hose to various connection on the boiler, at line pressure may be your best bet. It you can make a wand of sorts to reach into all the ports to dislodge some of the sludge.
A piece of tube with hatch saw slots to make like a car wash type nozzle to blast it out.

Leave the pressure relief valve in place so you don’t over pressurize the boiler.

Break the spiro in 1/2 also, it may be sludge inside.
!

Cherny

hot_rod said:

You need to get a good flow through that boiler to flush it out. The sooner the better. The Rhomar cleaner has softened the gunk. It will turn into a hard deposit if you let it dry and become almost impossible to get out. Like red cement! It is called hematite, the ferrous metals that have broken down from the O2 ingress with the PB tube. Connecting a hose to various connection on the boiler, at line pressure may be your best bet. It you can make a wand of sorts to reach into all the ports to dislodge some of the sludge. A piece of tube with hatch saw slots to make like a car wash type nozzle to blast it out. Leave the pressure relief valve in place so you don’t over pressurize the boiler. Break the spiro in 1/2 also, it may be sludge inside. !

Yes thank you. The spirovent has been deep cleaned and I got a new element for it as the inside was just a huge mess. The top I disassembled and rebuilt as well.

Everything else I've been able to disassemble and deep clean or I'm replacing.

I will try to flush out the boiler as you suggested.

Thank you again for the help.

JUGHNE

I am curious about your PB tubing.

I have PBOX (with oxygen barrier) installed in my house. (No problems yet).

What type of PB did you have in your house?

Cherny

JUGHNE said:

I am curious about your PB tubing. I have PBOX (with oxygen barrier) installed in my house. (No problems yet). What type of PB did you have in your house?

We had regular PB from 1986 with a mix of plastic and copper fittings. No oxygen barrier hence the inordinate amounts of rust in the system. Here is a picture of the tubing with some markings.



Made by Vanguard in Canada I believe (I'm in British Columbia).

The bigger leak we had was a couple of weeks after I ran hydrosolv through the system. Either that was enough to erode the tubing or the cleaner dislodged some of that hematite hot_rod was talking about and that exposed the tubing more than before. Or it was completely coincidental.

Either way, it's been a huge, expensive job but we're glad it's all out now. If you haven't had any issues you're probably ok still.

JUGHNE

Thank you, Cherny.
We have had this installed since 1995. Upgraded to Mod Con from CI about 10 years ago.

There was no issue with CI or blk piping at that time.

Cherny

So, for anybody else interested, I made a flushing wand with a short section of 1/2 pex (approx 3ft), with a plug in the end and a few perforated holes angled outwards and forwards. I hooked this up to a hose this morning and was able to flush quite a bit of hematite out. I inserted it into the supply as well as into the return as far as I could, with the pressure relief valve off so if could not build up any pressure. After several flushes from the top and the bottom I started getting mostly clear water out. I'm sure there's more stuff deep inside that is not getting dislodged but I'm happy it's clean enough to be hooked back up. We shall see how everything runs in a few days.

hot_rod

Cherny said:

So, for anybody else interested, I made a flushing wand with a short section of 1/2 pex (approx 3ft), with a plug in the end and a few perforated holes angled outwards and forwards. I hooked this up to a hose this morning and was able to flush quite a bit of hematite out. I inserted it into the supply as well as into the return as far as I could, with the pressure relief valve off so if could not build up any pressure. After several flushes from the top and the bottom I started getting mostly clear water out. I'm sure there's more stuff deep inside that is not getting dislodged but I'm happy it's clean enough to be hooked back up. We shall see how everything runs in a few days.

Good job!
I suspect some is baked to the surfaces inside the boiler. A thick layer can cause the boiler to percolate, a popping, sizzling, rumbling type of sound, similar to a gas fired water heater full of sediment. And an efficiency hit.

Cherny

hot_rod said:

So, for anybody else interested, I made a flushing wand with a short section of 1/2 pex (approx 3ft), with a plug in the end and a few perforated holes angled outwards and forwards. I hooked this up to a hose this morning and was able to flush quite a bit of hematite out. I inserted it into the supply as well as into the return as far as I could, with the pressure relief valve off so if could not build up any pressure. After several flushes from the top and the bottom I started getting mostly clear water out. I'm sure there's more stuff deep inside that is not getting dislodged but I'm happy it's clean enough to be hooked back up. We shall see how everything runs in a few days.

Good job! I suspect some is baked to the surfaces inside the boiler. A thick layer can cause the boiler to percolate, a popping, sizzling, rumbling type of sound, similar to a gas fired water heater full of sediment. And an efficiency hit.

Thanks hot_rod 

For what it's worth, the boiler was running quietly and seemed to heat up very quickly. I'm sure there's lots of crud in there still. As for efficiency I can't speak to it, our gas bills were all over the place but we didn't have the system running consistently well over the winter to put much weight on that.

The burners look clean and there were no deposits under the draft hood.

Once everything is hooked back up I plan to run it for a few hours and flush everything a couple of times to get any flux and other junk out. Should I pump any rust preventers in one it's all set? Or is that not necessary anymore now with PEX-EVOH?

Thanks again!

Derheatmeister

If you do not already have a Magnetic Device such as the Fernox TF1 i would highly recommed one. https://fernox.us/product/tf1-total-filter/

Cherny

Derheatmeister said:

If you do not already have a Magnetic Device such as the Fernox TF1 i would highly recommed one. https://fernox.us/product/tf1-total-filter/

That seems like a great suggestion. 

Unfortunately it's not in the budget. This has been a huge project and we're already over budget. I will add it to the future improvements list. While not ideal it seems like something that can be relatively easily added later on.

Thanks again!

Cherny

I was just thinking last night... I am locating the pressure tank and city water supply on the return side, and I have the 1/2"FIP port available on the bottom of a SpiroventJr available on the supply. Is there a magnetic plug that can be used on the bottom of the Spirovent? I realize it would not be nearly as affective as a true magnetic filter, but it may catch something. Similar to a magnetic drain plug on a vehicle's transmission/oil pan/etc? The spirovent will be located just before the pump and will have isolating valves on either side so draining it occasionally would not be a huge problem.