Eclassic 1400 plumbed through oil furnace without heat exchanger

[Roger2561]

I was at another site and I had my a** handed to me by another member who said it is not a good idea to plumb an open loop system through a pressurized system without an external heat exchanger.  He gave some compelling agrument but I am not a plumber so I have to trust he knows what he's saying.  The pro who installed my system did it without going through the heat exchanger.  Can anyone confirm who's right, the current system without the heat exchanger or I will need a heat exchanger?  Anyone chime in here and offer their 2 cents?   Thanks, Roger

[stratford 50]

My original set up was through my existing oil furnace. It will work but after a while my zone valves started to bang when closing. It should be two seperate heat exchangers in my opinion and the local plumbing contractor agrees with this. So we installed an additional heat exchanger and everything works fine. An oil furnace has around 12 - 15 pounds pressure in the system, compared to my outdoor furnace which runs none. Hope this helps, Paul

[pinebugsrus]

I just installed my Eclassic 2400 in January without the separate  heat exchanger and seems to be working fine but this will be a string I'm going to follow very closely.  It was suggested that I install a shut off to isolate the air vent atop my expansion tank and keep it closed while feeding the loop with the wood boiler and open it if I need too go back to the oil boiler only.  Then I would close the loop to the wood boiler and open the makeup water loop to pressurize the oil boiler.       

[Roger2561]

My original set up was through my existing oil furnace. It will work but after a while my zone valves started to bang when closing. It should be two seperate heat exchangers in my opinion and the local plumbing contractor agrees with this. So we installed an additional heat exchanger and everything works fine. An oil furnace has around 12 - 15 pounds pressure in the system, compared to my outdoor furnace which runs none. Hope this helps, Paul

That's what I was told too; the zone valves may begin acting up.  If you don't mind me asking, what kind of money would I have to expect to dish to out?  Installing it appears to be rather simple so that's something I think I can handle myself.  Thanks for sharing your story with me.  Roger 

[stratford 50]

My setup cost around 1500.00 installed by my plumbing contractor. He installed a plate heat exchanger some isolation valves and a small amount of fittings and copper pipe. It looks great and works well. Paul

[Holmes]

 Stratford 50 .. Unfortunately you installation is wrong. You do need a heat exchanger between an unpressurized and pressurized system. You will either lose the pressure in the inside boiler or overfill the outside boiler. Another problem is the outside boiler water is full of oxygen and that will speed up the corrosion of the inside boiler. I can list more problems if you like.   
    MY Mistake       This was supposed to be addressed to  Roger2561. Not stratford 50

[Roger2561]

Okay, it appears the consensus is to install the heat exchanger.  You'd think the pro who installed my system would have known better.  Anyone have an idea what size plate exchanger I need for my system?  It's 3 zones with baseboard heat.   Thanks for the help all.  Roger

[Holmes]

 You should go with a 100,000+ , btu's exchanger.  If you are making hot water also you can easily need 100,000 or more btu's per hour. Or you could go with the size that your boiler delivers for heat.  150,000? 180,000? 200,000, btu's

[boilerman101]

I still believe indoor boilers can be plumbed direct successfully and your installer did not take you for a ride. I'm certainly not saying there is anything wrong with using an exchanger, but am open to the following facts..... There are 1,000's of boilers plumbed direct from various OWF manufacturers. Most show both options in their owners manuals or websites. Roger and I have Central Boiler products. For instance, look at a CB owners manual, CB Brochure or CB Website....CB shows install illustrations for both using Plate Exchangers and Direct Hook ups for boilers. Do you think a company as large as CB other established OWF companies that have been around since the early 1980's would show these diagrams if they were wrong or their customers were having equipment failures? I would doubt it.  Most of this negativism I believe is coming from closed pressurized system, old school plumbers (no offense) that don't understand what corrosion inhibitors can do to protect the metal throughout the system and have done so in open systems for years.  I also know for a fact you can feed upper level floors with a direct plumbed system and the water will not run over out at the lower OWF as long as no air can enter the loop and the water auto feed valve has been turned off.  A good example would be to put a straw in a glass of water, put your thumb over the top end, you can lift the straw up with the water in it until it breaks the surface. Only then will it drain out. Many of these "pressurized experts" also state you must use expensive brass pumps or cast iron pumps will fail in an open system. Again my 11 year old 009 Taco standard cast pump is still working fine (knock on wood)
If you still plan to use an exchanger, I would recommend a 5"x12"x50 plate exchanger if your existing indoor boiler is rated at 150,000BTU or less. Which it more than likely is. Again, I believe either install works and is safe with proper corroision inhibitor water treatment in either case and the dealer should probably go over both options and cost differences with the customer, allowing the customer to make the final decision.

[Holmes]

  boilerman brought up some good points  The correct answer to your question is if your boiler directions have a schematic showing the proper way to pipe the boilers together and the directions are followed exactly then the system is installed properly. All issues with boiler performance are based on proper installation including warranty.