Timing of Preemptive Boiler Replacement

dgoldstein

I have a Munchkin 80M R1 boiler with outdoor reset running fine.

It was installed by the previous owner/builder of the home in 2006.

I've serviced it yearly for the last 10 years. Replaced the blower fan last year. I've noticed the pressure relief valve port on the boiler's water chamber developing mineral deposits around the seal (o-ring is no longer available from HTP). I'm reluctant to open it up to figure out a replacement o-ring for fear of cracking the boiler housing.

I also replaced the pressure relief valve last year due to the valve seal leaking/mineral deposit contamination after a manual test opening. I always keep a new spare on hand.

I know many of the main wear parts are still available from Jupiter Heating.

Given it's age, at what point would you consider preemptively replacing it before it has a irreparable failure during the middle of a cold winter?

It heats one out of three connected zones for 6-7 months of the year here in NJ.

What's your assessment process on whether to replace an old, but working unit?

cross_skier

I'm not sure if there is anyway of knowing.  I joined this forum two months ago shopping for a replacement for my 23 year old Peerless steam boiler which is running fine.  After hearing about the 40 year old similar Peerless boilers owned by  @Hap_Hazzard and @AdmiralYoda I decided I would wait a few years.  Maybe someday Burnham will finally put a gas gun on that energy star rated Megasteam.

dgoldstein

@tommay - I just remembered that the pressure valve was leaking due to a failed expansion tank. Replaced that February of last year. No more valve leaks.

Nonetheless, how frequently do you open/flush/test the valve?

Daveinscranton

I would be ready at anytime to have to spring for a new boiler.  

If you are committed to keeping the Munchkin 80 running, I have accumulated a bunch of spare stuff.  Mostly used.  I had planned on keeping my Munchkin running forever so I didn’t have to re pipe.  You are welcome to what I have but the deal would be you would have to pick up (free) all of it.  Otherwise it is headed towards the dump.  My heat exchanger went.  I could not find a new or good used replacement heat exchanger.

 I believe that you would be better served with a new boiler this summer.  Or spring.  Let me know soon if you wish to travel to northeastern PA for a bunch of stuff.  Essentially 3 boilers.  

Only thing that ever went bad on mine was a pressure sensor….. until the heat exchanger went.

Best wishes 

dgoldstein

@Daveinscranton - thanks for the offer, but I don't think I'll be able to make it to you any time soon. I'm a few hours South East of you.

How your heat exchanger fail? Was it a leak, mineral deposits?

Were there any early warning signs? Higher pressures? Short cycling?

Jamie Hall

I tend to regard boilers as an "on condition" item -- that is, if it ain't broke, don't fix it. That, however, is based on several things which are related. First, I deal mostly with steam systems, and it is very uncommon for a steam boiler to fail catastrophically without giving some warning, assuming that one is paying attention. This is also true of hot water, but the warning signs are a little more subtle and very few hot water boilers are equipped to measure the rate or adding makeup water -- which is the most important early warning for any boiler, steam or hot water. Second the systems which I work with -- both steam and hot water -- are simple with the exception of one, and that one has two duplicate boilers either of which can handle the load except in very cold weather, and which are automatically alternated so that if one fails I'll know it before the other one fails. If you have more complex boilers, such as a mod-con, I'd be much more cautious as they fail sooner and much more often (that's the reason for the one duplicate boiler installation I have) -- and parts may well be unavailable for weeks, if ever. Third, all the properties I care for have a "bugout" plan: that is, if the heat fails I can freeze-proof them in less than 12 hours., and it is possible to heat all but one of them to life-safety levels without the central heating.

JUGHNE

One early warning for Munchkin failure would be loss of water thru pinhole in water tubes.
If you shut off the water supply and pressure drops, you have a leak somewhere in the system.

Early Munchkin's had a safety water pressure switch to lock out at some low number.
You could test that switch for operation, it throws up a code for low pressure.

If you suspect a leak in the heat exchanger, isolate the drain hose to a point where you can see it dripping.
Any water flow without boiler firing would be from leak.

Daveinscranton

It leaked.  Fire side of the heat exchanger.  Lost pressure in the system.  I never use auto fill.  I dropped in what I thought was a good spare with the help of a friend.  But that one had a condensate leak.  Not much. But the insulation never fully dried at the bottom of the boiler.

At that point I put in a Triangle Tube Instinct 110.  Which I love.  Lot of re piping though.

 I always paid attention to water quality, and boiler set up and yearly maintenance.  I got 14 years out of my Munchkin.  I believe that it was a troubled design and I think I got lucky.  My current boiler looks much more robust than the Munchkin.

You may or may not have warning signs of impending failure.  For me, the process of selecting a new boiler began with giving up on the old one.  The lack of a heat exchanger, anywhere, sealed the deal.

dgoldstein

@Daveinscranton - on mine the take-up water certainly isn't filtered. It's effectively tap water going in and has been for the last 15 years.

In the spring I'll run some tests and get some quotes for replacement. I'm sure the supply chain issues going on is hampering product availability so the options might be more narrow than ever before.

Glad you sorted out a new boiler that you like. What do you love about it? I'm pretty sure the Instinct has a stainless heat exchanger - or at least the current versions do on TT's site.

Daveinscranton

I am by no means an expert.  That said, in answer to your question, I like the Triangle Tube Instinct a lot.  Looks to me to be well made.  Nicely laid out.  Big cabinet.  Easy to get to everything.  Much better boiler fire tube design than the Munchkin.  Relatively insensitive to water quality.  Comes with a propane conversion kit.  And the heat exchanger is very low head.  And fairly simple.  The electronics are in a box, plastic affair, and I believe that it buffers the temperature swings in the cabinet.  I believe heat, and heat cycles to be the enemy of sensitive electronics.  The whole thing is very robust.  Nice display.  In text too.  Easy to use.  You can specify max fire rate.  I have mine cranked down to a max of under 40,000 btu/hour.  I called tech support about my application.  They couldn’t have been nicer.  The manual is well written.  Lots of optionality.  Default settings will get it up and running quickly.  Dialing it in will take some time.  My guess is that few mod cons get dialed in.  I needed a boiler.  Soon.  This was available so I bought it.  Zero regrets.  I am sure that there are several mod/cons that would have fit the need.  Had I known who to call in my area, I would have.  Getting up in years and recovering from injuries.   Install is everything with a mod/con.  Mistakes on the install and it will never be right.  Or live (long) and up to its potential.  I did look up the specs on the stainless steel used in the boiler.  Correct alloy for a long life.  Old chemist so I am prone to such things.  This one is sipping propane on long burns.

Best wishes with your new purchase and go with what your installer is the most comfortable.

dgoldstein

just a follow up to this post... I didn't replace the boiler yet. I didn't service it last season due to a lot of schedule conflicts.

I finally cracked it open this past weekend and found some moderate mounding of "coffee grinds", the back wall refractory was stained and barely hanging on it's mounting stud. There appeared to be some condensate leakage at the bottom of the burner door. Surely the grounds were inhibiting enough drainage and some condensate seeped out through a worn door O-ring.

I flushed, brushed and flushed again the coils. Flushed and cleaned out the condensate pump and then got to work attempting to replace the fiberglass burner gasket. I didn't see any evidence of system water in the flushing or squirting into the chamber - it'd be green since it's de-oxygenated.

Typically the four Philips bolts are a little tough to get out. Instead of stopping right there in the face of substantial screw resistance, I pushed forward and snapped the head off the last bolt and simultaneously cracked the burner door refractory too. And, also wore a piece of the burner covering off it's tube.

So, I ordered all the replacement parts totaling nearly $670. I'm not exactly thrilled and am taking this as a severe lesson in stopping sooner when the parts resist.

I spoke with HTP's tech this morning and they advised I try to get another 2 years/seasons out of it and then replace it during the summer. As of this moment the unit is 18 years old (manufactured in 2004). The only other weak spot I'm observing is the port O-ring for the pressure relief value connection to the HX has sediment deposits around it. The O-rings for this connection are no longer available, nor is the HX. So, if the relief valve leaks badly enough, replacing it despite applying counter pressure with a wrench is a risk to potential irreparable HX leakage.

In the lead up to investigating a replacement, I do intend to do my own heat loss calc with the SlantFin app. I'll at least get a ballpark on whether or not prospective quoters are trying to fleece me with obscenely oversized units. FYI - my DHW is via a good condition, 5 year old Bradford White 50-gal NG power-vent. I just checked it's anode and it still has at least 70% material left.

That all aside, I'm working to figure out what might be my preferred boiler brand if not HTP. I've had great tech support from HTP directly as a home owner. Parts haven't been a problem until this point other than those particular ones previously mentioned and I was able to upgrade the unit to Vision 1 ODR myself and program it.

It seems there are installers in my area for HTP, Lochinvar, Weil-McLain, Triangle-Tube and Viessman.

There warranties are all mostly equivalent. All have reported good customer service from various sources.

Are there any particular aspects of boilers from these manufacturers that you think I should consider?

EBEBRATT-Ed

as you are discovering the life of a modcon seems to be around 15 years so you have done well. even if the boiler is still good around 15 years sometimes less parts become hard to find.

Viessmann seems top of the line and a lot of people like Lochinvar & HTP. Weil & Triangle tube may be fine as well.

I would stay clear of Navian.

hot_rod

You might consider buying the replacement now if you can swing it. Availability may not be so good if it quits mid winter, and prices are still going up in the metals and electronics world.

dgoldstein

@EBEBRATT-Ed - according to the HTP tech, they typically see 25 years of service out of these. I think if I hit 20 years, that'll be a fair point to replace rather than push my luck and have a mid-winter failure.

@hot_rod - I think given the efficacy of the parts I'm replacing, provided the PRV doesn't leak and a "coffee grinds" clean-out after this season and do nothing else, I should be able to get at least 2 seasons out of it. Yes, I realize everything is getting more expensive, but keeping this one running as long as possible with as little further investment is always cheaper than replacing with new despite increasing costs. It's analogous to keeping a used car going vs. new car. Certainly a judgement will be made on how much farther I want to push and risk a potential irrecoverable failure, but based on what I see in front of me I believe I can get this a little farther down the road.