Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

New Boiler Install

Flingwings Member Posts: 8
Hi Guys, hope all are having a good summer. I was wondering if I could benefit from your knowledge & experience? Sadly after 18 short years my Weil-McLain P-568 boiler has died from a massive hemorrhage. My September job just got moved up to July! Bonus: I was here when it happened and less than 16 gallons of water had to be sucked up.

No surprise there as I saw the leak and just wanted to get through the winter.

Anywho... I am going to install a Slant Fin EC-15 Eutectic. My questions are related to my existing installs. Reading through various postings I am seeing there are different opinions regarding how the hydronic system should be set up. While I'm sure everyone has valid reasons for their preferences I just want to say that what I have worked fine. In the 18 years this system was running bleeding's were done on few occasions; renovations to the house that replaced baseboard, failed indirect hot water maker, failed auto fill & that's about it. I've never had a problem with air entering the system after bleeding. The circulators are installed on the return side of the system.

My questions are as follows:

1. I have 2 Watts 1 inch, 2000 cast iron check valves with plugs installed on the vertical riser. They are servicing the 1st and 2nd floor heating zones. The gravity feed override I"m sure seized long ago besides I have a generator and always a spare circulator on the shelf so no worries there. They were there when I put the P-568 in and I'm going to assume that they were installed when the house was built in 1963; 50 years! My question is should I change them? Obviously there is going to be labor involved here, it looks like one of those jobs where I'll need 2 men and a boy to accomplish!

2. Same question & condition on the indirect loop except that check valve is a Bell & Gossett SA-3/4" installed in 1995 with the P-568.

3. The air scoop; same deal, change it or keep it? I suspect it's originally installed in 1963. The auto air vent was changed in 1995 and still works but is getting changed. The bladder tank is getting changed as I destroyed it removing the boiler. Additional info on this:

     A. Bladder tank was installed directly under the air scoop. Looking into the tapping on the underside of the air scoop it appears that the splitting plate is intact.

     B. Should I relocate the new bladder tank to a wall or hang it underneath as it was? It 's a head banger where it is and there was a lot of sediment in the port of the bladder tank.

     C. If I relocate it does it matter if I mount the connection port on the top or bottom? Considering the sediment I found I'm thinking mount it port down and install a sweat Tee with a ball valve underneath to collect & occasionally purge the sediment.

4. The new bladder tank: How big should I get? If it matters  the home is a 2 story & I have 150 feet of fin & tube baseboard and the new EC-15 has about 12 gallons of water.

Thank you all in advance for your time & knowledge.


  • Harvey Ramer
    Harvey Ramer Member Posts: 2,217
    Sorry about your bad luck.

    Before you put a new boiler in, the same way the old one was, perhaps it would be a good idea to determine why the old boiler failed. That way you can make the appropriate changes when you install the new boiler.

    Where did it leak?

    Was it a cold start?

    How does the interior walls of the iron pipes or heat exchanger look?

    Was the system frequently purged?

    Is there a lot of rust debris in the bottom of the fire box?

    We're there any chemicals in the system, glycol...ect?

    Is your DHW tied in as well? If so, how? A separate zone or and indirect coil?

  • icesailor
    icesailor Member Posts: 7,265

    I'm the heretic here.

    P568's have an indefinite life. Especially if they don't have a tank less and they are run as "cold Starts". I define "indefinite" as failing the day after the install under warranty, to outliving the homeowner. It can fail at any time.

    It ran for 18 years with minor repairs. 

    Get prices with a basic boiler replacement and additional alternates with additional pricing so YOU can decide what you want to pay for. It might be nice to put in new circulators but if your exposed heating pipes are un-insulated, you will get far more money for your dollar than just replacing the circulators.

    The more options people are given, the happier they are. They feel that they have some control in their big expenditure. I always gave multiple prices and options. People never chose the cheapest, basic, and not the most expensive. But somewhere in the middle.  
  • Flingwings
    Flingwings Member Posts: 8
    Why Weil Mclain P-568 Failed?

    The reason it failed was most likely 2 fold:

    1. I've since learned that the elastomer O-rings used between the sections in the  Weil-Mclain 68 Series boilers were defective & prone to failure. I could get this replaced under warranty but I have no intention of EVER giving Weil-McLain any business after learning what their warranty policy is: Buy a new boiler, fill out the paperwork and pay the supply house $100 to process the claim and about 2 weeks later Weil-Mclain will make a decision. I assure you If I bought anything other than a Weil-McLain boiler the claim will be denied.

    2. I have a well for water supply. I learned that I have acidic water with a ph about 6.2. That was not always the case as I had the water tested many years ago.* I've since added an acid neutralizer to boost the ph up to about 7.0/7.2 which is basic.

    There were no added chemicals, just well water. The boiler was not a cold start. It was always hot as I have an Amtrol  41 gallon  hot water maker on the above mentioned indirect loop. I'm finding that cold showers are invigorating!

    As for he rest of your questions:

         Where did it leak? Between the 4th & 5th section

    Was it a cold start? No 160/180

    How does the interior walls of the iron pipes or heat exchanger look? No clue not look but I will if it matters.

    Was the system frequently purged? See my original post for that run down but I would say no.

    Is there a lot of rust debris in the bottom of the fire box? No. The original leak was discovered 2 years ago when I went on vacation in the summer. I was going to be gone for 3 weeks so I shut everything down including the well. I came home to a puddle under the boiler. Not a big mess as at that point it was just  a drip. that left a 3 ft. puddle from unpressurized water dripping. Had I not shut the boiler off I'd not known for a year or 2 as the water turned to steam when it was hot. We found the leak using a bright LED flash light & a 3" inspection mirror that I use on aircraft. you had to put the mirror under the boiler and look up

    We're there any chemicals in the system, glycol...ect? No just well water which turned acidic.
  • Flingwings
    Flingwings Member Posts: 8
    Prices and Options

    Get prices with a basic boiler replacement and additional alternates

    with additional pricing so YOU can decide what you want to pay for. I did and I've done my research. My choices were a Buderus Logano 115 or the Slant Fin Eutectic. I'm going with the Slant Fin as I've not had good luck with Bosch electronics be it car parts or appliances. Bosch owns Buderus.


    might be nice to put in new circulators: I would but these Taco's work fine and I have ball valves installed above and below the circulators. I swear Tacos are bullet proof!

    If your exposed heating

    pipes are un-insulated, you will get far more money for your dollar

    than just replacing the circulators.  I'm not sure what your trying to say. Are you trying to tell me to insulate the pipes? They are for the most part..

    One thing that always puzzled me was when I would go on vacation and shut the boiler off I would come home to water on the floor due to a tripped relief valve that didn't reset. You know how they can be, sometimes they trip and seal up, other times the never reseat and drip. So I recall replacing that once or twice also. Any ideas why shutting the boiler off and allowing it to cool cause the relief valve to trip?
  • icesailor
    icesailor Member Posts: 7,265
    A trip:

    It sounds to me like you have had a failed Bladder tank for some time. That the internal pressures have been going wild. If the relief valve was popping open, the system was over pressurizing. Above 30#. As a rule, in hydraulics, the difference in water under pressure due to temperature rise, it is in-compressable and the difference between 1# and 1,000# is a drop. When you shut off the boiler for the vacation, the water is displaced by its thermal properties. When it cools, it constricts. It will go negative and atmospheric pressure will push in through the weakest link, the gaskets. If the room temperature rises any amount, or the radiation or piping. It will cause water expansion. The relief valve will pop because of the expanding pressure.

    I've not seen the issues that you describe with *68 series boilers. If you weren't careful cleaning them, you could knock the sealant between the sections. The biggest source of leaks was at the tank-less coil gasket The red rubber gets as hard as a tar road and leaks.

    Failed Extrol type bladder tanks kill a lot of heating boilers.
  • Flingwings
    Flingwings Member Posts: 8

    Interesting thought on the bladder tank. That just may have been the case. If so it will be taken care of with a new tank. Tell me what you recommend for maintenance inspections on the bladder tank? Every time I was in the basement to do Laundry I walk past the boiler and the pressure always showed 10 - 12 psi, and yes the gauge does work.Do you have any thoughts on replacing the check valves? Are they a bullet proof assembly or should I go with new ones?
  • icesailor
    icesailor Member Posts: 7,265
    Under Pressure:

    If the fill valve is working and maintaining 10# to 12#, it will always show 10/12# on the gauge. If the pressure drops below 10#, the fill valve adds water.  Bad Extrols can kill a boiler. If the PRV blew and stayed open, the system pressure hit 30# Sometimes, they don't blow until over 40#.

    Take the cap off the Schrader valve and push it down with a nail or screw driver. If yiu have air, it might be OK. If you get water, its shot. Drop the pressure in the system by draining some water out of the boiler. If the pressure goes to zero almost right away, the tank is shot. When it gets to zero, if you still gat air. Measure the pressure with a tire gauge If it isn't 12#, you might be able to add air to get it up. If it doesn't have any air at all, the tank is shot. If it is a #30 Extrol or equal, with all the additional water in the system with the wood heater or whatever you have, a #30 or equal is too small. You need at least  #60. It makes a difference.

    If it is the original tank from the original install, it surely worn out.
  • SWEI
    SWEI Member Posts: 7,356
    Before you decide

    Has anyone performed a heat loss calculation on the house?

    When you replace the boiler, you replace the air elimination device and the expansion tank.  Not doing so falls into the penny wise and pound foolish category and is almost certain to result in future unhappiness.
  • Flingwings
    Flingwings Member Posts: 8
    edited July 2014
    Heat Loss Calculation

    I agree with your advice to replace the expansion tank. Moot point as I destroyed it taking it off of the air scoop. One thing I've since learned is the air scoop needs to be reconfigured as it was located 6" from an L that was on the boiler supply, (you probably know this but it should be 18" minimum, regardless I never had an air problem on the install). Depending on how things things tine up I may have to use a more $ophisticated vortex air eliminator instead of an air scoop. Care to weigh in on the Watts check valves? While I hate to do it I'm leaning towards changing them due to their age. As for the heat loss, I downloaded Slant Fin's app for heat loss calculation and will be doing that today.
  • Flingwings
    Flingwings Member Posts: 8
    Flo Control Valve Selection

    While I have your ear do you have any insight regarding type & material of flow control valve valves? Looking over Bell & Gossett's offerings they have 3 styles that I think would work fine. They have the SA serries which is straight or angle, cast iron construction and many turns of the top control knob to override. The HT serries is bronze construction, straight or angle, and is only 1/4 turn to override. Both of these valves are NPT threaded assemblies. A 3rd offering in th SA serries is a straight bodied valve made of brass with sweat connections. Do you have a preference of one over the other? If so why or what are your reasons?
  • SWEI
    SWEI Member Posts: 7,356
    Check and other flow control valves

    depend in large part on the specifics of the system.  Is this by any chance a converted gravity system?
  • Flingwings
    Flingwings Member Posts: 8
    Gravity Conversion?

    I don't know what was done as part of the original system setup. The home was built in 1963, I bought it in 1992. At that time the Watts #2000's were already installed. I suspect they were put in to support the install of the Amtrol indirect hot water maker. All things considered I'm just going to bite the bullet and change them out. While I hate to mess with something that works, considering their age and the fact that the override knobs are frozen I think it's wise to change them. Parts with fittings should be less than $120.
  • icesailor
    icesailor Member Posts: 7,265

    Did you spray them with Kroil for a few days to see if they would loosen up? I've always been able to get things moving and set them right again.

    Patience is a virtue.