Add hot water boiler keep 1 as backup

quincy_trade_1956

Looking for info - book or articles with piping sketches on adding a new heating boiler while keeping old unit as a backup.

The existing is a propane Weil- McLain and new is up for discussion - possible Systems 2000.

I'm thinking primary secondary with both boilers piped in with only the new one firing and if backup is needed it would require a manual activation.

Info sources - idea's - comments ????

STEVEusaPA

well....

let me ask you this.  Why 2?  If the first one is fine, why replace?  If you're going to replace, why bother with keeping service/maintenance of the old, and all the extra piping, control strategies, etc, of the old unit, plus the new unit?  Are you somewhere so remote that you can't get some same day service?

If you insist, you're on the right track with a primary loop, and 2 boilers piped on the secondary.  Can your flue pipe, if needed, handle 2 units?

Control wise, if its purely backup, your going to need some sort of either/or switch to keep the controls isolated from each other.  The controls of 2 different systems just wont work together.  But this requires someone to manually switch.

As far as books, the standard great ones from Dan will always do....Primary/Secondary, and Pumping Away.

Al Letellier_21

two boilers?

I agree with the questions posed by Steve as to why and breeching size, etc. but as far as controlling two boilers, easy to do with a good control like a Tekmar. You can program each boiler to run as you wish, using the staging control and settings. We do this all the time with light commercial units, even when not the same manufacuterer. A TT call is a TT call and all the boiler needs is that call to run. I won't get into the debate about which boiler to buy, but you have a good one now, old or not, so why change???

quincy_trade_1956

Thank you for responding

To Steve,

Existing Weil McLain was installed in this house when it was built in 1989 and it is very reliable but low tech and I'm assuming I can get more bang from my fuel dollars with a new unit.  The annual service on this old baby is minimal as I watch the techs remove the burner tubes for a quick check and that is about it.   As to being remote I am located in northern New Hampshire and in the past we have had ice storms that put pressure on all the service people.   So if in the event the new high tech heating unit fails at a time of duress I could  just switch back to the old W McLain and ride it out till I can get service.  The existing flue exits through the side wall so no flue problems.

As to books your comments stimulated my mental juices and I went on a search for items I purchased at one of Dan's seminars long ago.   I located HOW COME, THE GOLDEN RULES and PUMPING AWAY which I had dated as August 1994.  It looks like I need to purchase PRIMARY/SECONDARY.   I had really enjoyed listening to Dan and doing imagineering with him as he laid his information on us.   I spent my piping years on housing stuff from 1959 to 1965 at whitch time I went to commercial work in Boston.   I still like to play with pipes at 73 and think I will install the second unit before the heating season this year if I can get my butt in gear.

Thanks to Al for control comments as the electric end of thigs always puzzeled me.  Too much fun piping so never got into controls.

A little story - I just burned wood this past year for the first time in a very large Jotul fireplace insert in our living room.   One eveing my wife asked why the shower water was not as hot as it should be.   Answer was the ignighter fauiled on the W McLain but the house was a toasty 70 degrees so I called for service in the morning.

So I may be headed for (3) sources of heat.

Bob                                                                                  

STEVEusaPA

still yanking on the wrenches at 73?

Well God Bless ya then.  Sounds like you're on the right track.  I hear ya about back up.  I'm on a dead end street, when the power goes out, we're the last one's to get back online.  So I have an oil-fired boiler, My A/C is set up with heat pumps, with electric back up, a gas fireplace that could get me thru, and a whole house generator.

I agree with Al that you could wire up both boilers with a Tekmar (I have the 374), but I thought you were looking to switch things over manually in the event of your new unit failing.  If you wanted to have it automatically work, you could wire both boilers to the 374, toggle 'rotate boilers' to off.  You can also put in a very long stage delay.  Should boiler 1 go down, the supply sensor  (sensing falling temp on a call for heat, and boiler 1 not working), would fire the second boiler.  You just may not know you're on back up.

Post a sketch, or reference a drawing from one of the books, and I'll be more then happy to help guide you.

quincy_trade_1956

Thanks for reading and responding again!

Thanks Steve,

As I had said all I have to do is keep getting my BUTT in gear!!

Today was a good day though - I was out in my 3.5 acre wood lot I bought next door making a logging road with my tractor - crowbar and shovel.   You have never seen such bouldery ground!   No wonder Northern New Hampshire has such great stone walls.

Last year I burned 5 cords and this year I am way behind as all wood should season (dry) for a minimum of 6 months after splitting.

Use it or lose it so they say and I do miss playing with all those pipes!!

Bob