# Boiler Pressure...



## PlumberPete (Nov 14, 2009)

I am stumped. I have a client in the last two days I have changed an expansion tank and replaced the automatic boiler feed. The pressure in the system still rises above 30psi and discharges. I have also shut off the valve to the tankless coil to see if there may be a possible leak in the coil. Any ideas here? The boiler is at least 60-70 years old. Is it possible that there is a slight leak in one of the sections and turns to steam before water is noticeable on the floor? Any info is appreciated.


----------



## Catlin987987 (Nov 12, 2010)

How are the pipes to the expansion tank? I have had rust blocking 99% of the 1" line going to the expansion tank, and it would pop the SRV all the time. I had to strip it back and replace the piping.


----------



## PlumberPete (Nov 14, 2009)

I cut out the old galvanized tank. Capped the line to the old expansion tank. I installed a new tank on the supply with an air scoop. All 1" copper pipe. Old lines were clear.


----------



## GrumpyPlumber (Jun 12, 2008)

Adjust the auto-feed down, if that doesn't do the trick and the tankless isn't the problem, there's no question the auto-feed is defective.

Edit: My mistake, missed the part you mentioned replacing the auto-feed - still, adjust the auto-feed for good measure....this is probably the tankless coil, it's the only other place that potable can inject into the closed system.


----------



## Gettinit (May 9, 2012)

What is the pressure of the expansion tank? There shouldn't be steam on a hot water system. Are you sure it is pressure related? Did you change out the T&P after the first blow out? If not checked regularly and is needed to blow they usually do not seat back well.


----------



## Gettinit (May 9, 2012)

There are no auto feeds on a hot water boiler....it is a prv. It may be defective....I assume there is at least one working ball valve on the domestic side...close it! Then that will rule out a bad prv. Is there a fast feed on the prv, the sometimes are left in fast feed.


----------



## GrumpyPlumber (Jun 12, 2008)

Gettinit said:


> There are no auto feeds on a hot water boiler....it is a prv. It may be defective....I assume there is at least one working ball valve on the domestic side...close it! Then that will rule out a bad prv. Is there a fast feed on the prv, the sometimes are left in fast feed.


Boiler feeds, commonly called auto-feeds, a type of PRV specifically designed for hydronic boilers, I don't know anyone who refers to a boiler feed as a PRV, it would confuse my supplier if I called in for a boiler PRV.

Watts 911....auto-feed, he'd immediately know what that is.

I suspect this is a leaking coil, he already has the valve off, so we'll know later on I'm sure.


----------



## PlumberPete (Nov 14, 2009)

We call PRV's auto feeds in CT. The fast fill is and has been closed. The relief valve was the first thing replaced. I have a feeling that it is the coil. It's as old as the boiler.


----------



## Gettinit (May 9, 2012)

CardinalPumbing said:


> We call PRV's auto feeds in CT. The fast fill is and has been closed. The relief valve was the first thing replaced. I have a feeling that it is the coil. It's as old as the boiler.


I must have misread, I thought you pulled it out already. Fast feed down or not I have had many get stuck. The coil is the only thing it can be if you are sure about everything else. If the pressure on the expansion tank is too high you may as well not put one in.


----------



## GrumpyPlumber (Jun 12, 2008)

CardinalPumbing said:


> We call PRV's auto feeds in CT. The fast fill is and has been closed. The relief valve was the first thing replaced. I have a feeling that it is the coil. It's as old as the boiler.


The first question I ask when a customer calls in for a relief blow-off is if they have a tankless or indirect so I know the boiler model/make, if it's a tankless, to make some calls while I drive there, gives me the chance to have a price handy when I arrive, in case it's not the autofeed.


----------



## Gettinit (May 9, 2012)

If I walked into a boiler supply here they wouldassume I was working on steam. Anyways, can't go wrong with a model number in hand....or the part. 

Tomato, tomato....that just doesn't work when typed out....hah


----------



## PlumberPete (Nov 14, 2009)

Ok. My next question is what is a less expensive option to replacing the coil? That coil is going to be a SOB to replace. I actually believe its a permanent part of the boiler now. I'm thinking whole new boiler. But I'd like to exhaust all reasonable options before we move forward.


----------



## Gettinit (May 9, 2012)

CardinalPumbing said:


> Ok. My next question is what is a less expensive option to replacing the coil? That coil is going to be a SOB to replace. I actually believe its a permanent part of the boiler now. I'm thinking whole new boiler. But I'd like to exhaust all reasonable options before we move forward.


If no money, cap and new water heater. Money, replace boiler and whatever you want. What type of heating system? Gas or oil?


----------



## PlumberPete (Nov 14, 2009)

It's an oil fired system. Capping it is probably out of the question. The entire boiler including coil plate is painted with old grey lead paint. Just too much work involved to pull the old coil out.


----------



## Gettinit (May 9, 2012)

CardinalPumbing said:


> It's an oil fired system. Capping it is probably out of the question. The entire boiler including coil plate is painted with old grey lead paint. Just too much work involved to pull the old coil out.


Cap the water lines and leave it in place. A torch and rag will take the paint off.


----------



## PlumberPete (Nov 14, 2009)

Lol. Ya ok. Cap the copper lines, the easy obvious answer. Too obvious I looked over it. Thanks. I'll fill you in Monday or Tuesday.


----------



## Gettinit (May 9, 2012)

CardinalPumbing said:


> Lol. Ya ok. Cap the copper lines, the easy obvious answer. Too obvious I looked over it. Thanks. I'll fill you in Monday or Tuesday.


Sorry, I thought it would be a viable option depending on available funds. I like Buderus boilers with a Weishaupt burner. Tankless for radiant or forced air applications.


----------



## rjbphd (Feb 5, 2010)

Ya trying to save a 90 years old boiler and indirect coil???? Can't imagae the effiecincy on that beast.


----------



## pilot light (Apr 21, 2012)

Try turning off the feeder! does it have an lwco!


----------



## RealLivePlumber (Jun 22, 2008)

Pressure test the coil. Then youll know fo sho.

If you took out an atmospheric exp. tank and replaced it with a bladder tank, I'm guessing you used a 15. Too small :yes:

Get yourself at least a 30. Or bigger. You got lots of system water there, grasshopper.

Be sure of what the problem is before you try to sell them a boiler. They may just get a second opinion. And the next guy may find out what the problem is.

Won't look too good if he does.


----------



## pilot light (Apr 21, 2012)

Is It an immersion coil !


----------

