Boiler replacement

mazz

Hello, I am new here but wanted some expect opinions & options regarding replacing a Weil - McLain boiler w/ indirect tank same brand that is 23 years old but in fairly good condition. Propane is used to heat the boiler & used to heat bottom concrete flooring ( 4,200 sq ft ) with 4-5 zones . My wife & I are currently under contract for this log home in Colorado area 7,200 elevation. This home is going to be our retirement home & plan on stay & living there year round . I’ve educated myself concerning radiant heating systems & new technologies concerning ECM technology pumps which can drastically reduce energy use & newer condensing boilers , ie HTP, Lochinver Knight, Navien etc etc . However I find many different t opinions & views on which system is the most 1. Reliable, 2. Low maintenance, 3 cost effective & 4 reliable customer service.
The original boiler can probably last longer but is cast iron boiler , older recirculating pumps that are properly not efficient running w/ higher watts etc etc.
I just want to make a wise decision & need some professional & experienced feedback .
Thanks ,
Mazz

hot_rod

What type of tubing is in the floor?

mattmia2

You might gain some efficiency, it isn't likely enough to pay for the cost of replacement. There are a number of valid opinions on mod con vs conventional boilers. Your current boiler could be nearing end of life or could last for many more decades depending on the design, installation, maintenance and water quality.

mazz

It’s PEX tubing on the floor in concrete.

mazz

Thanks mattmia2 ! Appreciate the feedback . I just found out that there are two (2) 175,000 Weil-McLain 23 year old cast iron boilers for this home & heating 4,200 sq ft on bottom floor ....isn’t this too much ? ?

mazz

They are both run by LP , Contracter said he would replace them with new condensing Lochinvar - Knight boilers at a cost of around $ & would give me a savings of around 250-500 per month in energy cost ......labor close to $ because both of these are located 2nd floor. New ECM pumps etc .....another contractor said I might be better off going Geothermal w/ water heater ? Higher initial cost but more energy efficient & 26% federal rebate .

GroundUp

Are you positive it's PEX and not Polybutylene,PAP, Onix, or something else? There wasn't a lot of pex being used yet 23 years ago but it's possible. Nobody can say for sure whether or not there is too much boiler without performing a heat loss analysis, but odds are pretty good even a single 175k is grossly oversized unless there's zero insulation and/or there's a ton of glass.

mazz

I am pretty sure but we are having a house inspection on Aug 10th since we are out of state in AZ & will be traveling there during each inspections . The original builder said it was insulated during the install in the concrete.....ton of glass ? ?

mazz

So when they are sizing the system how much is a heat / loss analysts cost ?

mazz

Here are some of the pics of just one of the boilers & system .....

hot_rod

Log homes can be a tough heat, it can be complicated to get an accurate heat load without a blower door test to confirm infiltration (air gaps). Also actual R value of the logs, how well they were insulated between the seams, etc.

The best info would be how well it has heated in the past, fuel bills etc.

Lots of glass?

You have good components, and it looks well assembled.

You mentioned 4200 sq on bottom floor? Is there an upper level at 4200 sq also? if so, two boiler at that altitude with a potentially high load building could be accurate.

Plenty of great hydronic guys in Colorado, might be worth contacting one for a load calc.

Maybe Zman on this list.

mazz

Thx ! The top floor is only 2,200 sq ft but is not heated by the radiant heating system , has a separate Lennox furnace & HVAC system , so I am not sure why there are two 2 175,000 BTU boilers for bottom level at 4,200 sq ft ? ? Gonna have to contact my plumber that did the assessment & recommendation to replace both with Lochinvar boilers ......

HVACNUT

You're only showing one boiler and one indirect. There's another boiler?

hot_rod

Any snowmelt, hot tub, pool? That is one reason you might have two. Are they in different sections of the home?
Maybe the Lennox has a hot water coil?

mazz

No pool, or hot tub, garage downstairs is a zone also for radiant heating , maybe that’s why ? It’s around 860 sq ft plus the 4,200 sq ft living area , total 5,000 sq ft downstairs 5 zones all downstairs same level concrete slap with PEX. Here are the other pics & other boiler .

mazz

Here’s a pic of the Lennox furnace near the 1st boiler

mazz

Here’s a pic of the Lennox furnace near the 1st boiler

hot_rod

The first boiler you showed looks like it is up in an attic space, under the roof pitch? It has mixing valves and probably supplies the radiant zones.
how many zones or thermostats in the home?

Where is the second boiler located ? Got a pic of the piping around it?

mazz

They are both up in an area near the roof pitch , one on each end of the log home . Sorry don’t have more pics of the second one until my wife & I get back there for more Inspections on Aug 10th, However my realtor might get me some more pics on Monday . Another contractor is going to give me an assessment then too, he suggested I might be better off with a Geothermal Install but will need to see if it’s feasible , enough open land area & retro fitting the existing system .....

mazz

Really appreciate your feedback, big decision we’ll have to make since this is going to be our dream home .....there are at least 5 thermostats , 1 in each room on lower level.

mazz

This was the only pic from second boiler , I know it doesn’t show much like the pic of other boiler .

HVACNUT

I wouldn't use geo as my sole heat source in a log house in Colorado. Stay with the hydronics. Properly sized of course. Maybe change the furnace to an air handler with a hydro coil.

mazz

Thanks HVACNUT , appreciate the advice, I’ll definitely check into changing the furnace to an air handler with hydro coil .......what life can I expect out of a Weil- McLain 20-23 year old cast iron boiler that has good components & has an indirect Weil - McLain tank as well ? ? Could I just replace the old pumps with new ECM technology to reduce the cost of electricity & wattage too ? ? 

mazz

GroundUp said:

Are you positive it's PEX and not Polybutylene,PAP, Onix, or something else? There wasn't a lot of pex being used yet 23 years ago but it's possible. Nobody can say for sure whether or not there is too much boiler without performing a heat loss analysis, but odds are pretty good even a single 175k is grossly oversized unless there's zero insulation and/or there's a ton of glass.

I’ll have an inspection on Aug 10th , GroundUp what if they did use Polybutylene, PAP, Onix or something else instead of PEX tubing back then (1997 ) in the concrete slab ? ? Can that be replaced or is it a red flag & probable pass on the cost for replacement & purchase of this Log home ? ? I can’t imagine the total cost to replace & tear up the concrete slab over 4,200 sq ft ?? 

STEVEusaPA

Might want to get all those VOC's away from the heater.

PC7060

The white piping that connects  your Indirect to the copper looks like Uponor Pex.  Can you read the label on the tubing where it comes out of the slab?

mazz

Thanks Steve , really didn’t notice ! ! I’ll definitely remove them to another place for storage . I tried reading the lettering in the tubing & it looks like it says AquaPEX ? I’ll be there next week on the 9th & get pics & have the inspections. Appreciate both of your feedback & comments . How much is it to service both boilers & indirect tanks ? I have two 175,000 BTU cast iron Weil-McLain units that are about 20-23 years old , not sure if it’s worth replacing both financially but would like to be more energy efficient with 2 new condensing boilers & new ECM technology pumps ??? 

Zman

If the heat tube says "aquapex" that brings up an O2 barrier issue that your inspector should be aware of?
What part of the state are you in?

mazz

The house is located in Pagosa Springs , Colorado .

Zman

The domestic water tubing appears to be aquapex which is good.
You probably have remote manifolds around the house that are connected to the 3/4" coming from the zone valves. You will want to verify the tubing connected to those. Most contractors were using Hepex or equivlant by the late '90s in Colorado. There was still a bit of Entran, PB and non-O2 barrier out there though.
Pagosa and Durango are kind of an island unto themselves. I am sure there are some good contractors down that way.

Zman

Keep in mind that the ProPEX connections in the photo did not exist in 1997. It has been replaced. You want to get eyes on the original tubing where it goes into the floor.

mazz

Hey Zman, thanks for the information & advice. I am trying to educate myself on hydronics & this system before our Inspections on Aug 10-12 & really appreciate your expertise & help concerning this system . I will definitely call you later in the week & I am sure I will have many questions . When we took the pics & viewed the property I really didn’t see any manifolds connecting tubing from the valves ? ? The system is located up on the second floor of this log home & has two (2) 175,000 Weil-McLain boilers & indirect tanks ( domestic water ) used for radiant heating on the bottom level 4,200 sq ft 4-5 zones . They also have Lennox furnace installed too, not sure if it uses hydro-coils for the heating but think they would of since using two boilers but will find out more later this week when were there for the inspections. Looks complicated but I am just trying to make sure what’s the best decisions to make and to have it as energy efficient as possible . 

JUGHNE

I built our house in 1996. We used the Weil McLain GV series 2
boiler. Yours is the next generation.
The literature I have states the AFUE of these at 87% efficiency.
They are a step above the standard CI boiler.

Something to keep in mind when comparing those to the modcons.....only maybe 10% difference.
They actually do produce condensate, mine has a drain tube where the exhaust exits the boiler. The port for it is between the air inlet and exhaust on the left side of the boiler. Also the SS venting pipe had a collection fitting where it exits the building.

It worked well, however in 2009 we went to a modcon. (If not in the trade we would still be using the 1996 boiler.
Taking the old boiler out it was inspected for damage from condensate. The only evidence was on the discharge horn of the exhaust. The series 2 that i had did have issues with the mixing valve to prevent this. Your series 3 has an improved system to prevent condensation from cool water returning to the boiler.

We also installed a few thousand feet of Polybutylene tubing in concrete and some walls. It was oxygen barrier labeled as PBX, is red in color, 1/2" outside diameter and well marked on the tube.
The oxygen barrier is important on any tubing.
While changing out to the mod con I inspected all the materials.
We have black iron pipe and copper feeding the system. Also 4 cast iron pumps that showed no issue with O2 penetration into the water that might cause corrosion to Ferris material.

With the 4000' of floor heat you must have several manifolds.
They can be remote from the boiler room....often are.
They can be hiding in a closet or behind a small wall panel.
Usually have 3/4 to 1" copper feeding the manifold which could have 6-8 tubing circuits connected to it.
If you find those where the tubing actually goes into the concrete that is the tubing you want to ID with good pictures of the manifold also.

Each manifold or zone probably has a thermostat somewhere in the house. If you could get a count.

mazz

Hey JUGHNE-
Really appreciate your input & information, very helpful........I can’t say how much this helps me to understand a system like this plus the fact you have the same Manufacturer ( Weil-McLain ) sounds like the series 3 are solid boilers with decent efficiency 80 plus % .....I guess it’s not cost effective to replace to gain only maybe 10% more efficiency for the cost ? Are the newer technology ECM pumps worth replacing to cut wattage & electric cost ? I’ll definitely learn more after a few inspections this week. Plan to take a lot more pics & ask many more questions. How much does it cost to service & maintain these type of boilers a year ? ? Obviously there are a number of valves, ignition parts , pumps etc . Just trying to get a handle on expected cost per year. I’ll also definitely check on the manifolds & where they are located......if you don’t mind me asking where did you build back in 1996 ? ? Anything else that you can add would be appreciated, thanks again.
Bob 

mazz

Do you have a pic on what those manifolds look like ? ? 

JUGHNE

The ECM pumps will save money on electricity......until you have to replace them later......ROI leaves pretty fast. IMO
Compare the prices and then how much less will they consume.
The little pumps you have now use very little power.

In the years that we used that WM boiler, IIRC, the only failure was the control board. I had one delivered and my 16 year old kid installed it while we were gone. Very simple.
It still had the original igniter/flame sensor when changed out, that is pretty good for a HSI....fairly fragile.

You might find someone familiar with that boiler and have them check out the exhaust horn for corrosion. There is a by pass pump inside to keep the return water temp high.
Other than cast iron sections it has: gas valve.....exhaust fan.....pressure switches....control board.....high limit control and the igniter/flame sensor.....and the bypass pump.

You want the water returning to the boiler to be above 130 degrees to avoid condensation by keeping the boiler hot.
Think of a car that does only short trips and never gets the exhaust system hot.....rust.

Our house is in North central Nebraska.
Just over 4000 sq ft heated with an 80,000 Btuh boiler.

If you find a manifold you will know it. 2 larger pipes feeding a gaggle of smaller tubes that go into the floor. Maybe with a pump and tempering valve. Perhaps individual flow controls for each circuit of tubing.

mazz

 Hey JUGHNE-
Really appreciate the feedback & getting back to me so soon ! I am looking forward in being there with the Inspector to ask a lot of questions , actually he’s very familiar with Weil-McLain boilers , as he highly recommended them to me as well. Thanks again . 

Mazz 

mazz

JUGHNE-

Finally was able to talk to the plumber who serviced both Weil-McLain boilers , he said although they are 20 + years old they have been reliable. However they installed (2) 175,000 BTU boilers & the other one is just used for a backup system in this Log home when it was being built back in 1997. Pagosa Springs , CO is at 7,000 ft elevation . They also put in  (2) septic systems for this home as well . 

The home is about 6,800 sq ft , on concrete slab, lower floor 4,200 sq ft with radiant heating. All systems are located on top floor different ends of home & both have Indirect tanks for domestic hot water. They also installed 2 Lennox furnaces that provide Heating & AC , was wondering how much it would cost to change them to use a heating coil since there are boilers used for the radiant heating ? 

Again, I’ll know more from Inspections this week but it seems 175,000 BTU Unit for only 4,200 sq ft is oversized but I am definitely not an expert or close to it .......will ask my Inspectors those questions . 

I could always just upgrade 1 & put in a more efficient condensing unit if it’s feasible & able to get a better ROI . They are both run on LP propane . I’ve read where using a heating coil for the furnace & AC is more energy Efficient ? ? 

Just trying to get the most efficiency & cost since this is going to be our retirement full time home. 

Any advice would be appreciated. 

Mazz 

mazz

I have two 20 year old propane gas Weil McLain boilers , do any of these Boiler Controls when added save on energy cost ? ?  Like Tekmar ? Or any other type of controls by other manufacturers that are proven to save energy ? Thanks 

mazz

mazz

Do these Boiler Controls help save on energy cost at all ? Especially on the older cast iron boilers I have ? Two Weil McLain boilers that are about 20 years old or are they a waste of money ?