Williamson OWT-3 Have replaced parts, ready to fire up?

Hello all !
I had a rather long thread over this boiler, and now different issues so I could
use advice on current issues before firing up!

History: Was overpressuring, leaking at the PRV. As advised, I've replaced the expansion tank, one of the auto air vents and a new boiler guage/tridicator.

Today:
- Adjusted the fill valve to 12psi "cold" "has been holding steady for hours"
- Adjusted the expansion tank psi. Bought a digital guage and checked what
was supposedly 12psi according to my tire guage, New digital guage read
23psi. Now reset to 12psi, proper.
- Feed to the HWC/hot water coil will be shut for now.

* Going to fire it up in a bit and post the results of that in a while. Getting pretty chilly in here!!!

Initially, I will adjust the aquastat HIGH to stop firing at 170F, set LOW 20F lower, and leave the DIFF at 10F. Wherever that may be on the dials I'll go by the boiler guage temp.

 

PRV generally means Pressure Reducing (or regulating) Valve. Do you mean the safety vale in this instance? If yes, did you replace the safety valve as well? Good practice is to have the safety valve tested or replaced every five years. Since the cost of testing often exceeds the cost of the new valve it simply makes sense to replace.

How do you know the old tire gauge was incorrect and not the new digital model? Very little precision in tire gauges so you need to find a means to test BOTH tire gauges against a known pressure.

I personally would set the LOW at no higher than 140 and the lower you can set it and still have an adequate amount of domestic hot water the better. Remember, the higher the standby temperature of the boiler the higher the standby losses. Also, the higher the standby temperature the hotter the initial flow from the thankless coil so unless you have a tempering valve (you should) set to a maximum of about 130 degrees F. the very real possibility of scalding hot water at a faucet exists.

As for the differential setting...I like as wide a differential as possible to reduce short cycling. Allowing the boiler temperature to drop lower before firing will give longer burner on cycles and also save on standby losses. There are ways to wire controls that will cause the boiler temperature to vary according to the cycling of the room thermostat in effect giving feedback control to set the boiler temperature only as high as needed to keep the home at the desired temperature.

 

Pressure Relief Valve/Safety valve was replaced last March, I just adopted the abbreviation "PRV" I see how it can be confusing so, being new to the terminology, I will pay closer attention!


I bought 2 digital tire guages, went to our small local airport and asked a guy if he would mind
checking them out against what they use. He said they weren't certified but the pkg stated
( +/- 1% + 0.5psi) both were pretty consistant so good enough!

With regard to the Aquastat settings; I kept the HIGH limiter to 170F because it made me a little less nervous, Lol for a trial run. The LOW just set at least 20F lower, and the DIF left at 10F until I learn enough to tailor the settings to my situation.. I'll certainly reread your explanation and add to my learning!

So! I did turn the boiler back on about 12 noon. Running great in my opinion and I'll summarize the
monitoring shortly

Thanks for taking the time to reply Furd! Anything I don't already know is a bonus!

Greg

 

THE UPDATE!

* I started the boiler from cold, 80F, boiler 12psi, tank 12psi.
* Boiler psi rose gradually, nothing erratic, pretty smooth.
* As temp neared 120F/130F began hearing air escaping from auto vents.

Progresses steadily 130F/15psi...150F/16-17psi...160F/15psi... fell slowly to
140F/15psi and hovered around there for a bit then gradually reaching
170F/15psi where I set the aquastat to stop firing. (Dial on aquastat said about 140F) Circulator is running. I set the aquastat to about 120F on the dial.
Circulator still running, Temp falling slowly.

Boiler refires, 145F/16psi...160F/16psi...170F/17psi...Circulator running

I monitored things pretty closely and after about 30 minutes just went about
my business. Everything stayed very consistent. It has been up and running since about 12 noon so I'm VERY relaxed! And WARM! Lol

I could have stopped banging my head, others too for that matter, had I just
put more importance in the guage I was trusting! Lesson learned.

So... much thanks and to everyone!

Next thing to do is open the feed to the Hot Water Coil..

 

I was pretty happy yesterday, thankful I'm getting somewhere finally, thanks
to the forum help I've had!

I had a look last night, just monitoring and noticed the boiler psi had creeped some and was now approaching 20psi at times.... wasn't too concerned considering it's had major surgery Lol

Today, about 20 minutes after satisfying a heat call it's at 155F / 23psi.

** Should I just continue to monitor "as long as it doesn't pop the relief" and
see if it's still getting air out?

Other than that, things seem ok!

 

T, give it time to see if it stabilizes. As long as it doesn't climb to much higher.
Is your HWC valve open. What you can try is shutting down and letting cool to see what cold pressure is. You said before it was 12 psi. If it's gone up by itself then something is feeding the boiler at a very slow rate but feeding nevertheless.
Without going back in the posts have you ever checked your feed valve to see if that's leaking by.
Would you be replacing that shutoff by yourself. Do you solder?

 

Hey spott..

NO, I haven't opened the HWC feed yet, had to replace the shutoff valve but it's ready now.

Funny, i just posted those results like 30 minutes ago, now i go check and after another heat call it cools off, and now settled back down to 140F at 12psi Lol

I replaced both main water feed valves with Sharkbite ball valves... they are rated for 200psi and 180F temps.

I did check the "regulator" THIS WAY > adjusted to 12psi, let stand overnight with the boiler feed open which is right before the backflow preventor+feed valve. Psi held steady for hours.
Does that tell me the same as if i had been running it with the water feed off?

* Boiler just came back on so I'm going to go down and see if it's changed AGAIN! Lol BRB
- It had just shut off as i was getting down there, stopped firing about 165F PSI now 23
Would i be correct thinking it wasn't a heat call because the circ wasn't on??

 

While it's on my mind...

I have to replace the PURGE valves. Original setup where it's a casting with a shutoff spout, and beside it a 1/4 turn shutoff. The spout on both are dripping occasionally "1 drop every 5 minutes or so, BUT, only when the boiler is off and fairly cool. Places like this that drip, are they also potential places the system can suck in AIR? Thinking maybe when the system cools it acts like a vacuum and might draw air in?

 

Correct, it was running on the low limit for DHW.

 

I wouldn't worry so much about the valve sucking air in unlike an air vent could but think about as water leaks out which eventually has to be replaced by fresh water that does bring air with it..That's one reason to have a leak free system.

 

I thought about that afterwards.. I must be learning something! LOL

With regard to Sharkbite fittings.. do you guys frown on them? I've used them on many things
and only had 1 straight coupling fail... My fault, I hadn't pushed it on quite far enough!

Yes I'll be replacing those purge setups ASAP, along with any other suspect connections etc.

The bleeders on some of the original fittings... if they are showing green corrosion, can the bleed caps just be replaced?

 

T,
I've never used shark bite so I have no opinion on that.
I have tried to get caps in the past without success. There's no money for these companies selling caps.
What I started doing was as I replaced leaking vents I saved the caps.
If you're changing purge stations because of a little leakage why not just buy hose caps.
As far as a little green on the vents, if they're not leaking just take some fine steel wool and clean and see what happens.
Green doesn't always mean a leak. If it's in a copper fitting there could have been excess flux that wasn't cleaned
or maybe installed with flux on hands from soldering which will turn green over time.

 

Ahh, good idea to save the caps!
I'm going to replace the purge stations anyway, there are "2" of them, just before each enters the long black 20 foot pipe returning to the boiler. Like a "Y" setup. Even to me that seems silly because that wouldn't flush/purge that long pipe! The basement purge is right by the boiler. Maybe it doesn't matter being more important that the baseboard radiators get flushed/purged? From what I've seen here though, most purge stations are pretty close to the boiler.

All these little things! I actually find all this info very handy to know so, no problem with
information overload Lol

 

I opened the feed to the Hot Water Coil...

Everything seems to be good except the water isn't that hot... maybe I
need to turn the mixing valve hotter! Wondering too if my aquastat settings will be ok, or maybe increase the DIFF some?

 

Your aquastat settings have everything to do with the temp of your DHW.
People can give you guide lines or suggestions but only you know how it's performing. Don't be afraid to adjust mixing valve or turn up aquastat to get the hot water you need.
Everyone's case is different.

 

I "basically" understand how the LO + DIFF work, as far as working out when, and for how long the burner reheats the water. I guess I can't hurt anything tinkering with the LO and DIFF so it sounds like you're suggesting I have to adjust them until I find i have enough hot water for what we use..
As far as the mixing valve goes, that just sets the temperature of the hot that comes to the taps?