Heating Help

York "Heat Pipe" Furnace

@ May 25, 2012 11:41 AM in Copper Flue piping

Does anyone remember the York Heat Pipe furnace from back in the mid '80's and all the problems it had? It used a copper coil in coil for the heat ex. and was about 85% efficient.
The flue and the heat ex. would rot out in short time.

Another "innovation" that looked good in the lab, but failed miserably in the field.

Hot Water Boiler

@ May 24, 2012 9:08 PM in What's best: Replace Radiator with Heat pump/HVAC or...

That looks like a hot water boiler on an old gravity flow system. Is there a pump on the piping near the boiler? Can you post a couple more pics showing the near boiler piping?

If I'm correct, then that's one of the best systems for a conversion to a modern boiler, but there are some things that will need to be addressed that most HVAC guys of today know little or nothing about.

Please see the attached article: http://www.heatinghelp.com/article/332/Gravity-Hot-Water-Heating/72/Gravity-Hot-Water-Heating-FAQ

Regarding Ductless Units: the cost of the equipment is substantially higher than ducted equipment, but when you consider that there's no duct work to be done, and no major surgery to the house's finish to be concealed, the total installed price is usually the same or lower than a ducted system. Plus, you'll have a system that's much more efficient, zoned, balanced and more comfortable. I've yet to have a customer that wasn't well satisfied with a ductless that we installed.

We come across houses like yours quite often and the solution is almost always the same: modernize the hydronic system and install ductless mini-splits for A/C or ductless heat pumps to provide mild weather heating with the hydronic system as main heating source.

I'd recommend that you consider a gas (propane) modulating/condensing boiler like the Dunkirk at the bottom of the page under "Product of the Month". A mod/con is the ideal match up for a converted gravity flow system.

Ductless A/c

@ May 23, 2012 11:25 PM in What's best: Replace Radiator with Heat pump/HVAC or...

Have you looked into using ductless mini-split A/C's like Mitsubishi, Fujitsu, etc.? These can be individually controlled from each room or zone and are much more efficient than ducted systems.

Definitely keep the rads and the hot water. They can also be controlled at each rad with TRV's.

I'm a little over two hours from you, near Staunton, VA.

I see One Other Thing

@ May 23, 2012 9:20 PM in Hallmark Furnace Issues. Looking for advice.

It appears that there have been 4 thermostats put on since January. Has anyone checked the current draw through "R and W"? You could have bad wiring between the t'stat and the furnace or a bad holding coil in the relay or primary control.

Also, the formula of Btu output / (delta T x 1.08) = cfm. will confirm how much air flow you have. Use a single thermometer placed in the supply duct that's out of a direct sight line from the heat exchanger to take your delta T. Start only the fan with no heat and take your first reading, then start the burner and take the supply temp after the heat exchanger is hot.

Also, use a little investigative deduction and check beyond the appliance itself. Is the thermostat being effected by another heat source? What time of the day does the problem occur? Is the customer using a second heat source? Is there something blocking the return grille? Is the blower motor shutting off mid-cycle due to a bad cap or weak overload?

You need to think out of the box on this one and stop running the same bases that have been gone over repeatedly.

I Am A Licensed Electrician...

@ May 23, 2012 8:44 PM in Electrical question

And what MikeG told you is correct. I'll add one other important detail: the neutrals must be wire-nutted together and pig-tailed to any outlets, not carried through the screws and bridge of the outlet. The reason for this should be obvious: if the neutral was carried through the outlet and you had a loose connection, that would send 240 volts to everything in the circuit. There's also the personnel safety factor.

Some locales are limiting the use of multi-wire branch circuits to appliances. I'm not sure if that's in the NEC as I seldom do house wiring any more.

Multi-wire circuits are safe as long as a novice doesn't tamper with them, in fact, every house with a single phase service is is fed with a multi-wire from the pole!

Again, as mentioned, make sure the hot wires are connected to opposite phases or the neutral will be overloaded. The neutral only carries the imbalance of current between the phases in the circuit when connected to opposite phases (if phase A is carrying 16amps and phase B is carrying 14amps, then the neutral is only carrying the imbalance of 2amps); but if the hots are connected to the same phase, the the neutral is carrying the sum of both phases. In this example that would be 30amps (16 + 14 = 30). This is another reason for using a 2 pole breaker: it assures the hots are on separate phases.

Thanks for the correction Mark

@ May 17, 2012 11:03 AM in Cleaning water boiler system before installing condensing gas boiler

I knew it had to be one of you two very clever gentlemen and you were the one that came first to mind.

Regarding the amount of rust produced by using non barrier pex: I've gone behind others who have done this and found the results extremely damaging.

I just installed a Knight WHN in place of a Munchkin Contender that was 2 years old and was connected to 7500 feet of non barrier radiant floor piping. The heat exchanger was leaking like a sprinkler and the MBR was plugged with rust. All the piping is coated with about a 1/16 inch of rust. But the installer saved a few $$ by using non barrier pex! I isolated the new boiler from the system by using an indirect and will return next week to begin the clean-up of the piping.

I'll post some pics after then.

Flushing System

@ May 16, 2012 6:13 PM in Cleaning water boiler system before installing condensing gas boiler

Bob,
I would recommend removing the old boiler and flushing the system before the new one is installed.

I would first flush with plain water until it runs clear on each loop. Then, if needed, use chemicals as needed and recommended by their manufacturer.

A lot of debris/rust, etc. can be removed with white vinegar and a pump cart. A very cheap but effective method.

If the piping is too complex to flush each loop separately, then there are chemicals that can be temporarily left to circulate in the system, but I would still try to flush as much out as possible with the boiler disconnected. Also, install a strainer or dirt separator as close to the boiler in the return line as possible.

As JDB pointed out, Rhomar has some good products.

Fernox is another very good product. Boyertown Supply is carrying it. Fernox also makes a filter with rare earth magnets that is great for collecting rust and iron debris.

Mark Eatherton also has a method of using a chemical feeder with magnets placed in it that he's posted here previously.

Paul

@ May 3, 2012 12:40 PM in Critical article on Tankless water heaters

Can you post a link to the article?

Thanks

Happy Birthday...

@ May 3, 2012 10:24 AM in Hey Mark Eatherton !

To both of you "old timers" :)

I turned 57 on Monday.

Won't work

@ May 2, 2012 11:05 PM in Navien DHW Increase

That only works with a tank where the volume of water is stored. On an tankless, you're limited by the max btu's output divided by (Delta T x 500) = gpm.

The flow restrictor orifice and your water pressure are going to determine how many gpm are going through the heater. The max. firing rate is going to determine what the temp rise (Delta T) is.

Raising the setting on the aquastat is only going to increase the output temp when there is a partial draw and the gpm is reduced.

Amorphous Pieces of Crud

@ April 30, 2012 12:13 AM in Weird debris in Lochinvar HX

I like your description.

The intake air connects directly to the combustion blower inlet on the WHN and therefore anything that is drawn into it (dirt, dust, bugs, pollen, etc.) gets burned.

I've noticed that all the boilers that use this direct connection seem to have more debris in the combustion chamber than those that don't.

Agreed

@ April 26, 2012 8:56 PM in Can we split tankless on-demand hot water unit for hydro air & domestic hot water?

I concur with Tony about the combi unit.

To answer your question directly: no, you cannot use a tankless that way. The hydronic must be separated from the potable (legionella). The tankless is not designed to have anything but cold water entering it: as in 50 - 55*. Not hot, not warm, but cold. It is not controlled for hydronic, but domestic heating. Also, the heat exchanger has an extremely high head that an ordinary hydronic circulator cannot overcome. It's also an illegal installation because the tankless is not A.S.M.E. certified for space heating.

Here's my usual response to this question: "If a tankless could take the place of a boiler, then there would be no need to make boilers."

Get a combi unit that is certified as a boiler (Navien, T.T., etc.).

Quality

@ April 13, 2012 12:41 PM in is there a difference in the pex tubing

Like anything else, higher quality requires a higher price. The cheaper brands are chinese and some of them are first class junk.

There are three basic grades of pex: type A, B or C. Type B is the lowest. Type A is expandable (like Rehau) and has a life expectancy of 200 years.

I personally prefer to use pex-al-pex in slab because it's easier to control and keep in place, but it also has different levels of quality.

Considering how permanent a slab is and how difficult if not impossible it is to repair a tubing failure, I would only use the best. The cost is not that more if viewed from the total job cost. The risk is not worth saving a few cents per foot.

They say a picture is worth a thousand words. Look at the one attached.

See attached link

@ April 10, 2012 9:17 PM in Navien Combi opinions wanted

Here's a link to a recent thread that I posted on this:

http://www.heatinghelp.com/forum-thread/140263/Navien-Combi-Boiler#p1257426

Correct

@ April 1, 2012 11:15 PM in heating dilemma - oil, gas, radiant, forced air, old house...

You can control the room temp. at the TRV. If Runtals or panel rads are used, they can be connected to the same loop (zone) if sized properly.

If you install forced air in a house like yours, you'll probably go from scratching your head to pulling your hair out after you've done it and have to live with it.

I'm in the Staunton VA area. There are some excellent guys on here who are in MD. "Steamhead" is near Baltimore; Dan Foley in Northern VA.

Another Option

@ April 1, 2012 10:41 PM in heating dilemma - oil, gas, radiant, forced air, old house...

Install a gas mod/con boiler connected to existing radiation. This could be zoned at each rad with TRV's. It would probably save 30 - 40% over your present setup with greatly improved comfort.

For a/c, install mini-splits where needed.

I wouldn't even consider forced air for heating when you already have a good hydronic system.

Where are you located in the Mid-Atlantic area?

Disadvantages?

@ April 1, 2012 9:56 PM in disadvantages

Does the name LEGIONELLA ring any bells?

It's amazing the dumb things people will do to cut a corner and save a $.

Side Arm

@ March 25, 2012 9:28 PM in Did I Make a Mistake?

Side arms work O.K. if piped correctly and supplied with 160* + water on the boiler side. They won't give the output or have the recovery that a plate has, but if sized right with a large enough tank, they'll work.

If you're only getting a 5* rise, then your piping may be incorrect. A side arm must be placed as low as possible and Tee'd in at the drain connection of the tank. The outlet must connect back to the cold inlet no higher than 4" above the tank. Remember, it works by percolation (like a coffee pot) so it has to be at the bottom with all potable piping pitched upward. Connect the hot boiler supply at the top with the return at the bottom and it should work fine. See the attached pic. (Not one of my installs).

Due to the size of your family (I have six girls and a boy) and tank, I think you'll be better served using the plate heat ex. I'd use the Webstone ball/purge valves advertised at the bottom of this page instead of unions. You should only need them on the potable side.

Heat Ex. Piping

@ March 24, 2012 12:52 PM in Did I Make a Mistake?

I don't know your line sizes, gpm or heat ex. size, but here are some rough guidelines:

1. I always use a 20 plate 5" x 12" heat ex. With proper flow rate on the boiler side, it will give you about 6 gpm @ a 77* temp rise. That's enough for three simultaneous showers.

2. If you have 1" lines (one set) coming in from the boiler, then run all the flow through the plate heat ex for the domestic first, then on to the space heating. This will give priority to the domestic which is the correct strategy. If you have two sets (four pipes) of incoming lines, then only run one set in series through the domestic heat ex.

3. If you have two heat exchangers and say 100' or so of piping between the boiler and the appliances, you'll need at least a Grundfos UPS26-99 circ. or equivalent. A lot of variables apply with pump sizing, but this is ballpark with the above parameters.

4. If you size with the above guidelines, the domestic heat ex. will pre-heat the water going into the tank to about 160 - 175* under most circumstances. The tank will dilute the heat if there's not a long draw and if the electric elements due come on it will only be after there has been no draw for many hours. When the do come on, they will only have to make up about 10 - 12*, not 75*. Therefore, the electric usage will be minimal.

5. With this setup, the longer the draw, the hotter the tank will get. You may want to install a tempering valve if you have small children or elderly folks in the home. This is highly recommended.

6. After the wood boiler is up to temp, open a hot water faucet and let about 50 gal. of water run out. This will fill the tank with hot water so the elements shouldn't come on unless there is a long idle period. A lot of my customers have told me they leave the circuit breaker turned off unless they're going away for several days and they never lack hot water.

Hope this helps.

Best wishes.

Why do You Need a Circ. on the Domestic Side?

@ March 23, 2012 9:40 PM in Did I Make a Mistake?

I can't see any reason for a circ. on the potable side of the heat ex. I install wood boilers regularly and when using a plate heat ex. we place it right at the tank and take the cold inlet and run it through one side of the heat ex. This way, when any faucet is opened, water is automatically drawn through the heat ex. and heated, then dumped back into the inlet of the tank.

If you're trying to keep the tank elements from ever coming on, that's not necessary. The amount they will run is minimal.

I've had guys do it your way after I told them not to and the results have always been the same: disastrous. You'll scale up the heat ex. and pump from the constant circulation of minerals and use more energy than if it was done as I described above. I'm not saying you won't have scaling doing it my way, but it will be 10 times worse the other way. Put a set of isolation / purge valves on the domestic side like those used on a tankless so you can de-scale when necessary.

Regarding using an iron circ. on an open system: it's a very bad idea. A picture is worth a thousand words. Look at these pics from a recent thread of a CLOSED loop that got O2 in it:

http://www.heatinghelp.com/forum-thread/140883/Anyone-seen-this

Some More Observations

@ March 21, 2012 11:12 PM in Lochinvar Knight boiler problems

1. The vent cap may be a concentric with the air intake going in under the part that looks like a storm collar. I'm not familiar with that make so that's a guess from looking at its appearance. I can't see an other purpose though for the collar having a gap between itself and the cone.

2. This brings up another issue: if the middle flue is active, the the exhaust from it would be drawn into the intake of the boiler through the concentric vent. If that's what it is.

3. it also brings up another issue: if the center flue is active, the heat of the exhaust gases could melt the concentric since it's plastic due to its close proximity.

4. I do not see the problems with the indirect piping that others here are stating. It may be there, but I cannot detect it from the pics. It looks to be according to Lochinvar's diagrams. Again, I may not be seeing everything.

5. Also again, the versaflow circ is definitely over-sized, but you'll need the heat loss for each zone to determine what size is needed.

6. Your current piping will be over-sized if your heat loss comes in with a substantially lower number (and it will) than what your boiler is. Don't panic. This is not a problem and the piping doesn't need to be replaced. It can actually be a benefit as it gives some buffer to the boiler which helps to prevent short cycling and puts less resistance against the circs. The only downside is that you don't want to get below 2 ft. per second velocity on a downward return as that might hinder air removal. If there are manual air bleeders on your rads, then it's probably not an issue.

Hang in there and be persistent and things will eventually get worked out. Stick to your guns about the heat loss and sizing - it will be worth the rewards in the end. An over-sized boiler is less efficient, costs more to maintain and operate, and will have a shortened life expectancy. Proper sizing will save you thousands over the lifespan of the boiler.

Please, keep us posted.

STEVEusaPA

@ March 21, 2012 10:25 PM in Lochinvar Knight boiler problems

Cricka,

Look up the above user name from other posts on this site and contact him. I think Steve is about an hour or less from you.

He's got a current reply posted on the "Radiant Heat" section.