New boiler advice

[David Paul]

My son’s hot water oil boiler with hot water coil needs replacing, leaking. 25+ years old. New to him house, boiler not well maintained. I’ve directed him to check out the available rebates/tax incentives for energy efficient replacements. I also suggested he look at any advantages to switching out the hot water coil to a stand alone hot water heater. Looking for any advice from the GJ group as to how to move forward and what to look for and what to avoid. It does not need to be replaced immediately so he can plan on the replacement. Thanks all.
Add: house is in New Jersey

 

[BigGarage]

My son’s hot water oil boiler with hot water coil needs replacing, leaking. 25+ years old. New to him house, boiler not well maintained. I’ve directed him to check out the available rebates/tax incentives for energy efficient replacements. I also suggested he look at any advantages to switching out the hot water coil to a stand alone hot water heater. Looking for any advice from the GJ group as to how to move forward and what to look for and what to avoid. It does not need to be replaced immediately so he can plan on the replacement. Thanks all.

I don't know what a "hot water oil boiler with hot water coil" is but if it's anything like the boiler I had replaced in 2019 then I can tell you that DTE gave me a $900 rebate for buying the most efficient boiler made. It was supposed to be 90% efficient but the label on it says it's 95% efficient. When it's in operation the PVC exhaust pipe is barely warm.

Dennis

 

[pcmeiners]

There maybe utility company rebates and federal energy saving tax incentives depending on the new equipment's efficiency rating. Read carefully the requirements. From info a couple of months back, the Feral tax incentive may require an energy audit by a professional this year, last year it was not required. Who pays for the audit for the Feds I do not know ? my electric utility company has one for free but I do not know if it is up to the Federal requirement.

 

[iced98lx]

My son’s hot water oil boiler with hot water coil needs replacing, leaking. 25+ years old. New to him house, boiler not well maintained. I’ve directed him to check out the available rebates/tax incentives for energy efficient replacements. I also suggested he look at any advantages to switching out the hot water coil to a stand alone hot water heater. Looking for any advice from the GJ group as to how to move forward and what to look for and what to avoid. It does not need to be replaced immediately so he can plan on the replacement. Thanks all.
Add: house is in New Jersey

Check out heatinghelp.com (note their rules, they are strict about not discussing pricing etc) but besides finding a contractor there is an absolute WEALTH of information available.

It SOUNDS like he has an oil-fed boiler with whats called an "Indirect" hot water heater. That is a coil of pipe comes off the boiler and sits in the hot water tank, when it needs to heat it turns on that "zone" and heats the tank.

In general hot water boilers (steam is a different animal) break down by fuel source (NG, Propane, Fuel oil) and condensing or non-condensing and then by the number of BTU's it puts out. Non-condensing is an older, less efficient style, where as a condensing boiler pulls more heat out assuming the operating parameters are met. Lots of room to argue about if operating parameters are met often, if one lasts longer than the other etc.

Overall, an LP/NG condensing boiler will be the "most efficient" but he may only really have access to heating oil, in which case they still make heating oil fired boilers.

I've bought a lot of stuff from https://www.supplyhouse.com/Boilers-449000 and they have good customer service. It's a big task to take on yourself, if you're not mechanically inclined. It can go from "pretty simple" to "very complicated" quickly as you work out zoning, making sure you have the right pipe configuration and pump location etc.

If you post a few pictures of the current boiler and piping along with which fuels you have access to over at heating help (or here) I'm sure you'll get lots of opinions on what to replace it with.

 

[pcmeiners]

Second Supplyhouse.com. During Sandy I lost my steam boiler. Worried the demand for boilers would be a big issue. Supplyhouse shipped a boiler out to me in a week. Install was simple but labor intensive, as I had to cut/thread steam/gas pipe. Luckily a friend loaned me a pipe threading machine, thank goodness.

 

[David Paul]

Thanks for the replies so far. Sorry if I was not clear describing the boiler. It is an oil fired boiler for the baseboard hot water heat. Within the boiler is a coil that is heated to provide continuous hot water, no separate holding tank. This requires the boiler to work all summer long to provide hot water. Oil and electric are the only fuels available right now. Rural area, no natural gas.

 

[fitter30]

I don't know what a "hot water oil boiler with hot water coil" is but if it's anything like the boiler I had replaced in 2019 then I can tell you that DTE gave me a $900 rebate for buying the most efficient boiler made. It was supposed to be 90% efficient but the label on it says it's 95% efficient. When it's in operation the PVC exhaust pipe is barely warm.

Dennis

Any condensing boiler gets its efficiency by the condensate 95+%. If return water temp is above 140° efficiency drops to 87%.

 

[danski0224]

Thanks for the replies so far. Sorry if I was not clear describing the boiler. It is an oil fired boiler for the baseboard hot water heat. Within the boiler is a coil that is heated to provide continuous hot water, no separate holding tank. This requires the boiler to work all summer long to provide hot water. Oil and electric are the only fuels available right now. Rural area, no natural gas.

Interesting. I did not know that there are oil boilers with a built-in domestic hot water coil.

What failed on the old one?

Near boiler piping is critical. If the return temperature is not above 140 degrees, there will be early failure of cast iron or copper tube heat exchangers. Slapping a new one in there without reviewing the piping is a bad idea.

The domestic water part might be replaceable.

I would strongly look at a heat pump water heater, it would be way cheaper to run in the off season than the oil boiler. You must evaluate hot water usage and make sure that the unit will meet your needs. Recovery rate is slow in heat pump only mode.

Or add a separate indirect water tank off of a regular oil boiler without the domestic water coil inside. Boiler is still needed to heat the water, but it should run much less.

No easy or cheap way out.

 

[David Paul]

Interesting. I did not know that there are boilers with a built-in domestic hot water coil.

What failed on the old one?

Near boiler piping is critical. If the return temperature is not above 140 degrees, there will be early failure of cast iron or copper tube heat exchangers. Slapping a new one in there without reviewing the piping is a bad idea.

The domestic water part might be replaceable.

I would strongly look at a heat pump water heater, it would be way cheaper to run in the off season than the oil boiler. You must evaluate hot water usage and make sure that the unit will meet your needs. Recovery rate is slow in heat pump only mode.

Or add a separate indirect water tank off of a regular oil boiler without the domestic water coil inside. Boiler is still needed to heat the water, but it should run much less.

No easy or cheap way out.

I’m only told it’s leaking. No pictures yet. I did tell him to look real hard at a hot water heat pump so we shall see. Thanks again.

 

[dave*99]

Propane? We just switched a house in VT from oil to propane. Supplyhouse.com sold us a Weil McLean condensing boiler, an indirect water heater and 4 Taco pumps plus all the trimmings.

 

[David Paul]

Here’s a picture:
Currently no propane

 

[danski0224]

Cast iron and copper fin tube?

Bet the return water temperature is less than 140* on the baseboard side.

It says "tankless" on it, but I picture nothing but problems just dumping cold water into it, unless it is inside of the cast iron part and surrounded by water. Have not seen one before, or taken one apart. I am picturing copper tubes between two headers and fins on the tubes. Interesting.

It might be replaceable.

 

[dave*99]

Here’s a picture:
Currently no propane

The unit we replaced looked like that. That is the domestic hot water part.

The boiler man said the flanges were all pitted and he serviced it for the previous homeowner way too many times.

It was working when we replaced it. But looked like death warmed over.

 

[dave*99]

unless it is inside of the cast iron part and surrounded by water.

I believe it is sitting in the 180 degree boiler water.

 

[American Locomotive]

It's called a tankless coil, very common here in the northeast. It's just a little coil of copper that sits inside the hot water boiler. They require a special temperature controller that keeps the boiler hot 24/7. Also very common for the coils to fail, and start leaking domestic water into the boiler water.

It the coil is leaking, the usual "fix" is to just cut the copper pipes and install a standalone water heater. If its the whole plate assembly that's leaking where it bolts onto the boiler, it may be possible to reseal it if you can get the bolts out.

If you can't get the bolts out, my recommendation is to replace it with another cast iron boiler, and a separate heat pump water heater. The heat pump water heater will pay for itself because 1) Oil is expensive in the North East, and 2) You don't need to keep the boiler hot 24/7 like you do with a "tankless" coil.

 

[Jsf721]

I got a Buderus boiler with a Riello gun. My first winter and so far so good. I have 3 zones and I did have one circulator go bad.

Make sure the guy bleeds the system and comes back 3 days later to do it again. I had a cold night and it would not heat no matter what. They bled the air and all was good. Then 3 days later one zone was not making temp. They bled all three again and said since it was a walls open almost complete re pipe it can happen.

2 months later the main floor would not heat, I though not again but a circulator went bad and I’ve been good since then December 7th was the circulator replacement.

 

[brewchief]

I got a Buderus boiler with a Riello gun. My first winter and so far so good. I have 3 zones and I did have one circulator go bad.

Make sure the guy bleeds the system and comes back 3 days later to do it again. I had a cold night and it would not heat no matter what. They bled the air and all was good. Then 3 days later one zone was not making temp. They bled all three again and said since it was a walls open almost complete re pipe it can happen.

2 months later the main floor would not heat, I though not again but a circulator went bad and I’ve been good since then December 7th was the circulator replacement.

With proper piping and a proper air separator air isn't an issue, unfortunately many installers don't know how to do it right.

 

[pcmeiners]

"If its the whole plate assembly that's leaking where it bolts onto the boiler, it may be possible to reseal it if you can get the bolts out."

Loads of fun. Removed the heat exchange in my boiler due to a boiler plate leak on my 28 year old coal fired boiler and iron oxide build up on the exchange. 6 bolts snapped off out of 12, had to grind broken bolts flat, drill out and thread for new bolts in a tight area. Then the high heat silicone used for a gasket shrank when cool and leaked slightly. Switch over to all heat pumps so I never repaired the leak. Coal *****.

Heat pump water heater....
Have a heat pump water heater and love it. My large basement is unused, 26x50, which has enough floor and wall surface for the water heater to pull heat from, at approx 50 degrees F year round, joist are insulated. As a result the HP water heater is not pulling heat from the living area above it. In most of the usa they should save a few hundred dollars a year IF you place it in an unheated area, which is not parasitic on a heated area of the home, as in a large unused basement which draws heat from the average ground temperature. HO water heater also act as a high capacity dehumidifier

As concerns bleeding air from hydronic systems your best off getting high capacity bleeders as linked. The small air vents, as usually used, are almost useless, they leak and take much longer to clear the air from the system. I used multiple vents, as linked, on my hydronic system and multiple vents ( water pressure rated) on my potable water piping

Bell & Gossett 79 3/4 In (M)NPT or 1/2 In (F)NPT 75 PSI Hydronic Air Vent (AW) | eBay

This is a Bell & Gossett hydronic air vent. Item Hydronic Air Vent. Connection 3/4 in (M)NPT or 1/2 in (F)NPT. (F)NPT Connections (In.). (M)NPT Connection (In.). If it is not possible we will work with you to resolve the issue.

www.ebay.com

or, newer technology

Honeywell PV125S 1-1/4 Sweat Connection SuperVent for sale online | eBay

Find many great new & used options and get the best deals for Honeywell PV125S 1-1/4 Sweat Connection SuperVent at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[zak77]

I'd also recommend going the heat pump water heater route vs trying to repair that leak, granted it appears something needs to be done to stop the leakage. I was in a similar situation where i had a tankless oil fired boiler for FHW and domestic hot water. I decided to get a heat pump water heater and that cut down on the oil usage but not completely because it still had to run to maintain temps if i called for heat, which i dont since i burn wood. My coil cover plate was leaking a little if i shut down the boiler for a couple weeks so i knew the gasket was bad but like yours, it'd be a PITA to remove since i'm sure some of the bolts will snap. Considering the boiler's 34 years old i decided to shut it down completely and if i decide to go back to FHW heat, i'll have a new boiler installed. Ran oil tank dry, drained system, and now just need to blow out the line and empty any other oil/sludge from the tank.

 

[Jackfre]

Tough situation. Yes, get the hot water on a separate system. I would hate to buy a new oil boiler in today’s world. I’d hate to be stuck buying oil for the next 25 years as its use is declining, the quality of the oil is questionable with all the bio, etc and it is service intensive. LP, in order to keep the hydronic heat, is about the only option unless NG is available. I don’t know how handy he/you are, and as pointed out getting the tankless coil out of the boiler and resealing it would be a *****, but If you can do it put a new gasket and cover plate on it and the HX on the boiler is not leaking elsewhere, he can get through the season and maybe get more life out of the system. Personally I’d drop a “right sized” Buderus LP boiler in there, buy a 500 or 1000 gal lp underground tank and get the oil out of the house.

 

[David Paul]

I have forward this information to my son. I’ll let you know what he decides. Good information, thanks all

 

[Jsf721]

With proper piping and a proper air separator air isn't an issue, unfortunately many installers don't know how to do it right.

Can you tell me what an air separator is ? I have not completely paid the contractor as if yet as he has a 36 point punch list he is working his way through. Is this something that should be standard ? Can it be added after tbe fact.

Thanks

 

[pcmeiners]

"Can you tell me what an air separator is ?"

I left 2 links to air separators/air vent in my previous post

 

[brewchief]

Can you tell me what an air separator is ? I have not completely paid the contractor as if yet as he has a 36 point punch list he is working his way through. Is this something that should be standard ? Can it be added after tbe fact.

Thanks

The brass device above the grey expansion tank is the air separator, it's piped in what's termed pumping away, done this way it is almost impossible to airlock.

 

[Jsf721]

The brass device above the grey expansion tank is the air separator, it's piped in what's termed pumping away, done this way it is almost impossible to airlock.

Does this remove air from the system ?

 

[brewchief]

Does this remove air from the system ?

Yes, they work very well. Within 10 or 15 minutes of startup you won't hear any air. Part of that is the air separator and part is in the piping design. There is a book called pumping away that explains it and it really works.

 

[Mr onetwo]

Do not, I repeat...do not replace the existing cast iron boiler with a typical propane condensing wall hung boiler.They do not work well in this scenario. It will never condense and the heat exchanger will not like it at all.If he decides to stay with an oil system Viessmann and Biasi make really nice oil boilers. https://www.viessmann-us.com/en/products/oil-boilers/vitorond-100.html https://qhtinc.com/brands/biasi-products/b-10/ Crown makes a top of the line indirect water heater...the MS2-40 https://www.acwholesalers.com/Crown-Boiler-Co.-MS2-040/p103185.html The advantage with these is you can incorporate outdoor temp setback and warm weather shutdown to save fuel. I like Tekmar for those functions. If you want to convert to propane I can suggest the Lochinvar Noble series of fire tube boiler. Works great on 180 degree baseboard systems and doesn't seem to care if it doesn't condense. https://www.lochinvar.com/products/residential-boilers/noble-boiler/

 

[Mr onetwo]

I think Spirotherm works a little better...it was the original air eliminator. https://www.supplyhouse.com/Spirotherm-VJR125-1-1-4-Spirovent-Jr-Air-Eliminator-Threaded-3561000-p

 

[David Paul]

And yet more good information. Thanks Mr onetwo

 

[Mr onetwo]

Just trying to help out.My body don't work no more but my brain sortah does