Teledyne Laars Minitherm bypass question


  #1  
Old 01-26-10, 03:15 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Question Teledyne Laars Minitherm bypass question

I just bought an old house. It has a Teledyne Laars Minitherm boiler. I brought in a boiler/furnace specialist to take a look at the boiler. They told me that the bypass should not be on all the time. They said that this will decrease the efficiency of the boiler. They say it was used mostly for preventing condensation on the water pipes during the spring.

I then read some posts in this forum, and it seems that the bypass should be on, in order to maintain proper flow to the boiler. This doesn't really make sense to me, since a bypass should direct flow from the input to the output, bypassing the boiler. I think I am missing something here.

I read the manual, and it seems that the bypass should be mostly on.

Can anyone please explain what the bypass is for, if I should keep it on or off, and does it look like this specialist doesn't know what he is advising.

Thanks in advance,

Fed
 
  #2  
Old 01-26-10, 03:22 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Fed, I'm sorry to say that your specialist is off base. They apparently are not familiar with the unique requirements of copper tube heat exchangers. ALWAYS follow the manufacturers recommendations, even if the conflict with a so-called specialist!

They say it was used mostly for preventing condensation on the water pipes during the spring.
This is a totally bogus statement... couldn't be further from the truth, and evidence that they either haven't got a clue, or are totally BSing you.

The bypass on a copper tube boiler is there to insure the proper flow rate through the boiler... and if it is NOT open the proper amount, the boiler can, and probably will, be damaged.

a bypass should direct flow from the input to the output, bypassing the boiler. I think I am missing something here.
Yes, SOME of the flow is going direct from the input to the output of the boiler... that part is true. However, it is not bypassing the BOILER, it is bypassing the SYSTEM. It is not properly called a BOILER BYPASS, it is a SYSTEM BYPASS... there are both types, and yours SHOULD be a SYSTEM bypass.

To be correct, your circulating pump should be on the boiler side of the bypass piping.

If you would like, post some pics ... free account / www.photobucket.com / upload there, drop a link here for us to view the album... we'll take a look at the piping and see if it all looks OK.
 

Last edited by NJT; 01-26-10 at 03:48 PM.
  #3  
Old 01-26-10, 03:45 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks, I just re-opened it. It was off for about 3 hours. That should be fine, shouldn't it?

He also opened the blue knob that allows water into the system and bypassed the intake pressure valve (by holding open a switch of some sort) while I bled the top floor radiator. He told me that the blue knob should be left open for proper functioning.

Is this wrong as well? And it the system now too pressurized?

Fed
 
  #4  
Old 01-26-10, 04:06 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
It won't have been damaged it in three hours... should be fine...

Not sure which blue knob you are talking about?
Post some pics and we'll look it all over for ya.
 
  #5  
Old 01-26-10, 04:50 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
The blue knob is the water main inflow to fill the system. The automatic valve is immediately after that. I guess it is to prevent over pressuring the system. Sorry I don't know the proper terms.

I cannot figure out how to post the pictures I took, sorry.

Thanks for your patience,

Fed
 
  #6  
Old 01-26-10, 05:09 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
No problem on the pics Fed... you can't put the pics here directly, you need to put them on a free photo hosting site such as PHOTOBUCKET (click here to go there) ... go there and set up a free account and upload the pictures there... when you are at the main page of your photo album, copy the information in the address bar of your browser and paste it into a message here... then we can go to your album page and view the pics... for example, my album page:

Pictures by JeffPicks - Photobucket

OK, I understand about the blue valve now... the bell shaped thingy after that is called many things (some of them not so nice!) but 'Pressure reducing valve' , 'automatic water feed' , 'pressure regulator' .... and probably lots more I can't think of at the moment. It's purpose is to establish a MINIMUM pressure in the system when it is COLD. The pressure will increase when the system gets HOT because of the expansion of the water, and this increase is controlled by the 'expansion tank'... the reducing valve is usually set at 12-15 PSI when the system is cold in MOST homes... only on three story and taller homes will that minimum need to be increased.
 
  #7  
Old 01-26-10, 05:14 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
So should that blue knob (I think it is the Feed Water Inlet) be open or closed?

Also, he must have opened the Pressure reducing valve while I was bleeding the top floor radiator. Could this increase the pressure in the system too much and cause damage? Should I somehow now reduce the system pressure?

Thanks again,

Fed
 
  #8  
Old 01-26-10, 05:19 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
There is a long standing debate about whether or not to run with the feed water inlet valve open or closed. There are pros and cons to both ways... leave it open for now, and we'll talk about that in a bit...

There is a handle or a lever on your reducing valve that will bypass the regulator and allow water to flow in faster to facilitate bleeding and filling a system. I'm sure he did not leave too much pressure in the system... it's possible, but I doubt it.

Take a look at your boiler and find the pressure and temperature gauge... tell us what the readings are, both Temp and Press ...

I gotta log off for a bit, be back later...
 
  #9  
Old 01-26-10, 06:43 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Pressure seems to be 27 psi, and temp is 50C (120F).
 
  #10  
Old 01-27-10, 04:29 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
27 PSI at 120 is quite high... IF the gauge is accurate.
 
  #11  
Old 01-27-10, 04:51 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
It is now 20 PSI at 120F. I did notice that it was 8 psi at 120 earlier today, just before the furnace started up again.
 
  #12  
Old 01-28-10, 03:58 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
It is now 20 PSI at 120F. I did notice that it was 8 psi at 120 earlier today
OK, something is screwball here...

At the same temperature, you can't have 27 PSI one day, and 20 PSI the next day, and then 8 PSI a while later... UNLESS:

1. Your pressure gauge is an evil, lying, demon from hell, (many of them are!) and it's just not true. It's usually the pressure part of the gauge that goes bad, but in this case, it sounds as though the TEMPERATURE part of the gauge is bad... like it's STUCK at 120... have you EVER seen it anywhere other than 120? In fact, it wouldn't surprise me the least bit if BOTH parts of your gauge are pooched.

2. You have a leak somewhere.

EIGHT PSI is WAY TOO LOW a pressure, and is likely the REASON that you needed someone to bleed the air out of the system. but,

Let's back up a bit... what prompted you to call in the specialists to look at your system? Was there some problem with it? It would help us to know some history.

What else, besides bleeding your radiators did they do?

Did they check the condition of your expansion tank?

We really need those pictures if you want us to help you.
 
  #13  
Old 01-29-10, 05:17 AM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
The Pressure is now 22psi, and the temp 160F.

Ever since the guy opened the Feed Water Inlet there has been water coming out of the Pressure Relief Valve intermittently. So I shut the Feed Water Inlet. Now there is still water coming out the Pressure Relief Valve intermittently.

He did not check the expansion tank. It seems a bit warm. Could it be full?

I called him in to see if I should get a new boiler, actually. I just moved into this house. He did not d maintenance. He just started moving things around.

I will try to get the pictures up today.

Thanks again,

Fed
 
  #14  
Old 01-29-10, 02:25 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Here you go:

The "blue knob" is the Feed Water Inlet on circled on the right in the picture and the intake pressure valve is on the left.




Boiler is shown here with the same circled objects:



This is another view of the boiler




And I was also wondering about the rust. Someone told me it was electrolysis because the system is cast iron, and the boiler is copper. Which one is it?






The Gauge is here




The Pressure release valve is here. This is where the water came out




Thanks again,

Fed
 
  #15  
Old 02-01-10, 05:23 AM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
I've been monitoring the pressure and temp over the weekend. It looks like the pressure is around 10 psi with the system cold, and it jumps to 30 when heating. This is when water drains from the pressure release valve.

I have shut off the water inlet (what I have been calling the blue knob). I was adding water to the system when I notice that the cold pressure is bellow 10psi. I think that this ends up getting release out the pressure release valve when the system heats.

I am wondering if the expansion tank is full. It does not sound hollow when I tap on it.

Any advice would be helpful.

Thanks,

Fed
 
  #16  
Old 02-01-10, 02:49 PM
T
Member
Join Date: Jul 2009
Location: Toronto
Posts: 1,043
Upvotes: 0
Received 0 Upvotes on 0 Posts
Sounds like its full to me.
If we are talking about a ceiling mounted air cushion tank then,,,
Shut off the boiler and isolate the tank, then drain it right down. This will take time, I have only ever seen one air cushion tank in ontario with a bleeder on the top to speed things up.
The tank is going to gurgle and split and make all sorts of noises until it's empty.
If its a pre-charged tank, you will need a new one most likely. Find the valve on the bottom of the tank, the one that looks like an intertube filler.
Press it in, if water comes out it's done. If no air comes out you might be able to pressurize it, but I doubt it. Either way in needs to come off and tested and recharged or replaced.
 
  #17  
Old 02-01-10, 03:20 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Fed, you probably have two things going on here...

1. For what appears to be a large water volume system, you have a very small expansion tank, and that tank is probably NFG.

2. You may also have a pressure reducing valve (the B&G gold colored one on the water line) that is leaking through and over pressurizing the system.

Someone told me it was electrolysis because the system is cast iron, and the boiler is copper. Which one is it?
Looks like a leak to me... probably from the 'union'... it may not be leaking any longer, but it might. Don't worry about that right now.

One thing at a time though...

The main problem is the expansion tank right now. Unfortunately, there is no valve on the line between the system and the expansion tank, so if you do have to replace it, you will have to drain the system. In fact, you will have to drain SOME water just to check the pressure...

And, like I said, it's very likely that the tank is too small for the system... it appears to be a '30' size, and given what I can see in the pictures, I'm willing to bet that even a '60' size will be marginal.

Do this first: on the bottom of the tank is an air valve... it's a regular tire valve... just for a half a second, push the pin in and see if you get any WATER out of that valve. If you do, then you know that the bladder inside the tank is shot, and you need to replace the tank. If you don't get any water, you can try pumping it up ... so let me know, and then we'll talk about how to add the air to the tank.
 
  #18  
Old 02-01-10, 03:26 PM
C
Member
Join Date: Dec 2009
Location: ny
Posts: 24
Upvotes: 0
Received 0 Upvotes on 0 Posts
make sure the pressure is 0 before you attempt.
and that tank weighs 40-50 lb full .
i just had to change mine and its above head above the boiler so i had to lean in over the boiler and it pushed to the right some on the way down ... even though i was ready, still surprising
 
  #19  
Old 02-01-10, 03:26 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
TO, ya snuck in aheada me agin!

Back up a few posts and you'll see the pics... it's a puny little 30 size tank on what appears to be be a converted gravity system!

So Fed, pay no attention to what the man behind the curtain said about the ceiling mounted tank...

Good point Cape! it's often a good idea to have a helper at the ready if you suspect a tank full of water!
 
  #20  
Old 02-02-10, 06:34 AM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
I pressed on the expansion tank valve, and I got air out, with a bit of water sputtering as well. This was with the boiler off, and the pressure at 10psi.

I noticed that there is no more water coming out of the pressure release valve if I shut off the water feed (blue knob - what is this called anyway?). But then the top floor rad has air in it at times. Is the top floor rad operating like an expansion tank?
 
  #21  
Old 02-02-10, 03:22 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
If yer getting water, you should replace the tank. You might 'get away with' adding some air, but it won't last long. If/when you do replace the tank, I really think you should consider a bigger tank, but there might not be room for the next size up in the current location.

I noticed that there is no more water coming out of the pressure release valve if I shut off the water feed (blue knob - what is this called anyway?). But then the top floor rad has air in it at times. Is the top floor rad operating like an expansion tank?
The reason no more water is coming out is because with the valve closed (call it a manual water feed shutoff? close enough) you aren't adding any water... but the problem is that when the boiler cools, the pressure is going too low and allowing air to collect in the upper floor rads. Remember that the higher in altitude you go, the lower the pressure goes. You lose about a half a PSI per foot. So, if you only got TEN PSI in the boiler, you have like ZERO PSI up at 20' above. And that lets the air come out of the water and form bubbles.

If your expansion tank was working properly, you would always have a minimum of around 12 PSI in the system, and a maximum of say 25 (probably not that much though) when the boiler was hot.

You need to do something with the tank. That's the bottom line.
 
  #22  
Old 02-02-10, 04:16 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
I'm bringing in the Laars maintenance guy in a week. Do you think that the system will be damaged by waiting that long?
 
  #23  
Old 02-02-10, 04:25 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
No, probably not, but changing an expansion tank ain't 'rocket science', and most likely that is all you need to do...

If you feel unsure of your abilities to change the tank, that's understandable... but just don't go spending a ton of cash just because you need a new expansion tank...
 
  #24  
Old 02-02-10, 08:04 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
The boiler hasn't been serviced in 3 years. The Laars service people want $125 CND to service it. I don't know how much the repair will cost.

Could you please let me know how often should it be serviced?
 
  #25  
Old 02-02-10, 08:24 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Actually, for your peace of mind, that may be a small price...

A gas fired boiler can often go much longer periods of time than an oil fired, which should be done yearly. If a gas fired boiler is kept in good repair by fixing problems as they arise... I would say every three years or so is probably a good schedule.

Be sure to mention to the technician that it's almost certain that the expansion tank is shot, and probably too small...

And, please beware that the technicians may also be salesmen. They may try to convince you that it's time for a new boiler... I can't say from here if it is, or isn't... but my impression is that right now, at this moment, you can probably just have the expansion tank changed and get through the winter... this is not the time to be replacing heating systems... that's work for the spring and summer.
 
  #26  
Old 02-03-10, 06:14 PM
T
Member
Join Date: Jul 2009
Location: Toronto
Posts: 1,043
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by Feddar
The boiler hasn't been serviced in 3 years. The Laars service people want $125 CND to service it. I don't know how much the repair will cost.

Could you please let me know how often should it be serviced?
This is where they tell you it's corroded, and unservicable.

I hope not though.

There does not appear to be a system bypass, or P/S piping. How old is the boiler ? Any idea ?
 

Last edited by TOHeating; 02-03-10 at 07:56 PM.
  #27  
Old 02-09-10, 11:28 AM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
The service guy just left. He cleaned the boiler, but didn't look at the plumbing. He said that I need to call another guy in to do that. I described the problem to him, and he felt that the expasion tank was fine. He said there is some internal safety system in the expansion tank that would turn the boiler off if there were a problem. He couldn't comment on the pressures or the need to bleed the third floor rad often.

He also said that my boiler was just fine. I'm quite happy about that.

Where should I go from here?

Thanks again,

Fed
 
  #28  
Old 02-09-10, 02:47 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
he felt that the expasion tank was fine. He said there is some internal safety system in the expansion tank that would turn the boiler off if there were a problem.
Complete, total, unadulterated BULL FECES!

He couldn't comment on the pressures or the need to bleed the third floor rad often.
Of course not, cuz he didn't know the difference between excrement and shoe polish!

Damn... I am totally disgusted with the state of the service trades...
 
  #29  
Old 02-09-10, 02:52 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Where should I go from here?
Unless you can find someone that knows WTH they are doing, and actually understands something about hydronic systems, you are going to have to learn how to change that tank yourself.
 
  #30  
Old 02-10-10, 05:23 AM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Is there any way to recharge it?
 
  #31  
Old 02-10-10, 05:29 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Earlier you said you got water out of the air valve, correct?

And I said if you got any water, that means the bladder is NFG...

So, my recommendation would be to replace it... if you try to recharge it, you will end up with more air in the system because it will leak past the bladder and into the system.

But I also said that it looks way too small for what looks like a large water volume system...
 
  #32  
Old 02-10-10, 05:33 AM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
OK. I thought I'd try...

So, I buy one (30 or 50 L) from home depot?
 
  #33  
Old 02-10-10, 08:16 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Let's go back a bit... just to clear up some points...

Your system is all cast iron radiators and very large piping, is that correct?

If so, I would recommend the 60 size tank.

If you decide to go with the 60, make sure you take measurements to see that it will fit in place of the 30. You may not find the 60 at HD (you might though...) so you might have to hit a regular supply house. Or, you could order it:

Patriot Supply - 1BN203

When you replace the tank, it would be a benefit to add a few optional items to the plumbing, and a support strap to the piping, those tanks get HEAVY when the bladder fails!...



If you had these items on your system already, it would be SOOO easy to change that tank, but as it stands you will have to drain the system to change it. This picture shows the tank hanging from an air scoop, just ignore that part... yours is hanging on an elbow.

If you can work fast, you might be able to get away with not having to drain the entire system... here's how:

Before you remove the old tank, turn OFF the boiler and allow the system to cool to under 100°F, close the water feed valve, and open a boiler drain to drop the system pressure to zero.

Assemble a nipple, and the ball valve, and put some pipe dope on the threads of the nipple... have it ready to grab and screw on... cover stuff with plastic... have a bucket nearby... wear a raincoat... you WILL lose some water... this works best with a helper... one of you removes the tank (IT MAY BE HEAVY! FULL OF WATER! BE PREPARED FOR THIS!) while the other quickly screws the nipple and the CLOSED ball valve into the elbow... then assemble the rest of the parts, tighten everything up... open the ball valve, turn the water back on to repressurize the system.

CHECK THE AIR CHARGE IN THE TANK BEFORE YOU INSTALL IT. If the factory air charge is less than 12-15 PSI, add air to the tank before installing.

All you need to do these options are

1/2" pipe nipples (2)
1/2" threaded ball valve
1/2" tee fitting
1/2" boiler drain

A couple pipe wrenches, some pipe dope (hercules mega-lock)

The support strap can be that perforated metal strapping that comes in a roll. Loop it around the pipe near the elbow and screw it to the ceiling above the boiler (into framing, not drywall!). Like this:



This picture is just to show the support strap... you won't be doing all this piping...

I think that's it...
 
  #34  
Old 02-10-10, 01:20 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks. I'll see what I can do.
 
  #35  
Old 02-22-10, 06:29 AM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Update:

Thanks for all the info. I ended up calling a plumber, and they wanted $350 for the job. I decided to do it myself.

Just before I left to buy the supplies, I tried to inflate the expansion tank anyway. So far, it is working just fine right now.

The pressure is now a relatively constant 15PSI. Is that too high? Should I now bring it down to 12, or is 15 ok?

Thanks again!

Fed
 
  #36  
Old 02-22-10, 02:13 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Fed, there's a little more to it than just pumping air in...

Anywhere from 12 to 15 is fine.

Here's some instructions. If you can follow these step by step, you should be able to properly recharge the tank. Remember, you can NOT get an accurate reading on the air charge if there is pressure on the boiler/water side of the tank.

If you get water out the air valve, the tank must be replaced.

============================

1. Shut off boiler and allow to cool to under 100°F.

2. Shut off water supply line to boiler.

3. Drain only enough water from the boiler drain to drop the system pressure to ZERO.

4. With an ACCURATE tire pressure gauge, check the air charge in the tank on the air valve opposite the end of the tank that's connected to the system. If ANY water comes out of the air valve, the bladder inside the tank is shot and the tank needs replaced. If no water comes out the air valve, and the pressure is less than 12-15 PSI, continue to step 5. If the pressure is OK, turn the water supply to the boiler back on and repressurize the system, turn the power back on to the boiler, no service is necessary.

5. Using a bicycle pump, or a small air compressor, add air to the tank until you have 15 PSI air charge.

6. Check the boiler pressure gauge again, and if it has risen off ZERO, drain some more water from the boiler drain until it is again at ZERO.

7. Check the air charge on the tank again. If it is below 15 PSI, add air to the tank until it is at 15 PSI.

8. Repeat steps 6 and 7 until the boiler stays at ZERO and the tank stays at 15 PSI. At this point, the tank is properly recharged and the water supply can be turned on to re-pressurize the system, turn the power on to boiler and return to service.
 
  #37  
Old 02-22-10, 02:23 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thank you so much. I will do this tonight when the boiler normally goes down to 100F anyway.

btw, there was no spike in the pressure this am when the boiler rewarmed the house.
 
  #38  
Old 02-22-10, 03:10 PM
T
Member
Join Date: Jul 2009
Location: Toronto
Posts: 1,043
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by NJ Trooper



This picture is just to show the support strap... you won't be doing all this piping...

I think that's it...
If you pipe the tank like this please put a tee at the top and an auto air vent above that. I have seen tanks ruined by trapped air. It causes them to rot out fast.
 
  #39  
Old 02-22-10, 03:28 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Yes, yer right... it's the same thing that happens when the tanks are installed inverted, with the air valve on top, or on their sides, horizontally. Thanks TO, I missed that! The drawing has been fixed...
 

Last edited by NJT; 02-22-10 at 03:58 PM.
  #40  
Old 02-23-10, 09:20 PM
F
Member
Thread Starter
Join Date: Jan 2010
Location: Canada
Posts: 39
Upvotes: 0
Received 0 Upvotes on 0 Posts
Great! I did it.
There was no water coming out of the tank 'bicycle like' valve when I checked this time, so I continued:

There are valves to isolate the boiler's in and out, so I shut them.
Then drained water (below 100F) until the pressure was 0.
Then pressurized the tank to 15psi.
Then drained more water, etc.

Eventually, there was no more water to drain.
I pressurized the tank to 15, then repressurized the boiler, then opened the valves.

Everything seems to be fine now.

Two questions:

1) Should I have not isolated the boiler?

2) Is Clockwise always closed in valves?

Thanks again,

Fed
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: