Help me to select a new(er) boiler control / aquastat for my old boiler.

MikeAmann

Oil-fired boiler.
Current controls:
Honeywell R8182D triple aquastat with an Intellidyne HW+ Fuel Economizer added.
The heating side is hydronic baseboards and is just one loop for the whole house with it's own circulator and no zone valves. This I have wired as a cold-start and I prefer to keep it this way.

I added a 40 gallon IWH indirect water heater to the system with it's own circulator. I built my own controller which is nothing more than a 3PDT relay that is activated when the LO Limit of the aquastat is reached (about 140 F), meaning that water no less than 140 can circulate through the coil of the IWH. If the IWH calls for heat, then one NO contact of the relay operates the circulator. Another NO contact sends the burner FIRE command. A third NC contact opens and interrupts the heating circulator, giving priority to the IWH.
If the water in the boiler is hot enough to satisfy any CFH, then The HW+ Economizer holds off the firing of the burner until really needed. I also added an LWCO for protection.


I have a 51 second cut-out relay connected to the ignition transformer to kill the spark after the trial-for-ignition safety circuit in the aquastat is satisfied.



I love my HW+ Economizer, and it works very well.
I noticed that a Burnham V8H boiler uses this controller:

Intelligent Oil Boiler Control

Combines aquastat and relay functions into a single module.
Two customizable integrated switching relays for easy addition of additional heating zone or indirect water heater.
Energy saving “thermal purge”, which works by circulating residual warm water (140° or above) in the heating system before firing the boiler.

I don't want to reconfigure and rewire everything. The K.I.S.S. principle definitely applies here.
Would a Honeywell L7224U be all I need to replace the R8182D? Are they relaible and what about the Resideo version? It's only $160 NEW at SupplyHouse.

SuperTech

Yes the L7224U would be all you need. It has all the capabilities of your old aquastat and the intellidyne, plus a few more including the ability to add outdoor reset. The Hydrostat 3250 is also an excellent choice and will do the same things as your current setup. 

MikeAmann

Thanks SuperTech.
I am doing my research now. I know I will have a couple of questions.

MikeAmann

So yes, the L7224U would replace my R81282D aquastat, and add a couple of features.
But the Hydrostat 3250-PLUS is so much more than that (I prefer the LEDs for easy monitoring), and I could retire my HW+ Economizer and external LWCO. I will replace my immersion well with the Electro-Well and add the outdoor reset.

I will be using this connection diagram.

Question: My hallway thermostat is a Honeywell ROUND. Compatible?

It looks like I will be disconnecting tonight so I can measure my current immersion well and get this order placed. Or, could I just pull the R8182D out of it's well, and insert say, a tig welding filler wire into the well until it bottoms out, and then just measure the length? Then I can reconnect the aquastat and still have heat until the new unit arrives.

STEVEusaPA

Yeah, land the 2 t-stat wires on T-T on the aquastat.
It’s probably just the standard 3/4” electro well.
https://hydrolevel.com/electro-wells/

HVACNUT

That's solved. Now what primary control are you going to use?

STEVEusaPA

HVACNUT said:

That's solved. Now what primary control are you going to use?

Might as well keep rolling with Carlin with a 70200.

MikeAmann

You guys beat me to it.
I was thinking about it last night and thought, "Hey, I don't remember seeing a CAD cell (F - F) connection on either of those controllers."
Does everyone agree with the above and going with the Carlin?

MikeAmann

I have 4 choices in Carlin:

Pro-X Universal Oil Primary Control (120 VAC)
70200S
$64.69 each
This is "too digital" for me. I don't have a cell phone, let alone a smart phone.

Interrupted Duty Oil Burner Primary Control w/ Alarm (15 sec TFI)
5020002S
$62.24 each
I like this, and it has built-in alarm contacts."

Oil Primary Control w/ Interrupted Duty Ignition, 15-Second Trial for Ignition
4020002S
$54.98 each
Same as above, without the alarm.

CAD Cell Oil Primary Control w/ 30 Second TFI Interrupted Duty
4223002S
$56.67 each

Oil burners use either interrupted or intermittent ignition systems. In an interrupted ignition system, the spark is active for a brief time at the start of the operating cycle, then turns off once there’s a flame. In an intermittent ignition system, the spark stays on while the burner runs.

I want interrupted. Should I choose 15 or 30 second TFI? Will this control play well with a Hydrostat 3250-PLUS?

MikeAmann

Is this what Hydrostat means by Short Insertion Length for Off-Center Immersion Well Tapping?


My tapping is off-center. I just need to worry about the well not being long enough to interfere with the tankless coil, correct? Nothing more to it than that, right?

I will measure, but the tapping for the gauge is to the right. It's 1/4".
So based in this pic, I believe I need a 1/2" electro-well.

Edit: I measured - it's 3/4" NPT.

SuperTech

I really like the ProX or Honeywell R7284U. I like that it can display the cad cell resistance readings. No matter what control you have I would want 15 second trial for ignition and interrupted ignition. You shouldn't have any problem having all these components work well with each other. It sounds like your boiler/burner renovation is coming along nicely. 

MikeAmann

Thanks SuperTech. I was looking at the connection diagrams of the Carlin primary controls and, although I would rather have the LEDs of the 5020002S, the 70200S Pro-X has two features that the others don't - a separate connection for the oil delay valve, and a post-purge function. I really like that each component will have it's own connection, instead of having everything wire-nutted together.

I just read the manual for the Honeywell R7284U and that also does everything that the Carlin Pro-x does.

So which one do I buy? Price is nearly the same. Which one does not fail? Easier to use? I like simple AND RELIABLE.
I am not ordering until I hear from the pro's here.

The oil-delay valve that I added uses the delay power cord (4 sec). I see that the Honeywell time setting for that can be changed - not sure on the Carlin.

Question: T-T connections - do I connect the wall thermostat to the Hydrostat 3250-PLUS only, or do I need to parallel T-T to the primary control also?

It's time to come out of the stone age. These controls have come light years from the controls I am retiring. I wired in separate units to try to add more functionality and safety, but only so much can be done with wires, timers, and relays. Now I get to unwire it all. But now I will have so much more control and functionality that is not possible with my old setup. This part will actually be fun.

MikeAmann

Bump TTT. Which primary control to buy? It will be paired with a Hydrostat 3250-PLUS and (wired) outdoor reset.
This is the planned order:

MikeAmann

Order placed. Items will arrive tomorrow.
But I can't work on it for a little while.
Lots to do this week. I gotta get Dad to the memory care facility - dementia.

SuperTech

You can't go wrong with either of those controls. With the 4 second delay cord I usually set up the controls for a ten second pre purge, that will give you close enough to the 15 second pre purge typically used. On boilers the thermostat connection is always at the aquastat, TT can be configured "on" with these controls so the burner will fire whenever the aquastat sends 120 volts to it. I often find a jumper wire installed on the TT terminals by guys who don't bother reading instructions.  The only time I have ever had to replace either control is when they have got wet. 

HVACNUT

What's the stainless hex plug for?

MikeAmann

I no longer need the Safgard 170 LWCO anymore, since this function is built into the new controls.
That is the reason for the new Electro-Well. The plug will block off where the sensor will be removed.

SuperTech - I agree with your recommendations for the pre-purge. What do you recommend for post-purge, since I now can enable that function? I like the idea of using post-purge. Why not?

MikeAmann

Any thoughts on what's going on with my expansion tank? https://forum.heatinghelp.com/discussion/185619/expansion-tank-not-taking-the-extra-pressure#latest

EBEBRATT-Ed

I would remove the tank and adjust the air pressure to the incoming city water pressure and try it again. But something doesn't seem right. The tank is acting like it has lost it's charge with that high increase in pressure. You should only get 1 gallon of expansion when heated.

Maybe there is something wrong with the tank internally

MikeAmann

I wonder if it being mounted "upside down" has anything to do with it? The directions say it can be mounted in any direction - even sideways. I will remove and test it. If NG, back to Home Depot for an exchange.

MikeAmann

I received the order today. So far I have the LWCO removed and the SS plug installed. And I disconnected most of the (now) unnecessary wiring and old R8182D aquastat. The old aquastat well didn't want to budge, even with a large 1-1/16" combination wrench. I thought about heating it, but I gave it a squirt of Knocker Loose and used a 6 point socket with the breaker bar that slides so you can apply equal force in opposite directions. It came right out. And the threads in the boiler were perfect. This was also part of the reason I went ahead and added the IWH - the tank looks fantastic inside. So the old well had black sludge surrounding it, which I removed and then screwed in a 3/4" NPT to garden hose adapter and flushed away until the water ran clean. Then I installed the new Electro-Well with Rectorseal ONLY - no teflon tape. BTW, the new well has the same dimensions as the old well. That's it for now.

SuperTech

For furnaces and boilers connected to a chimney I usually go with 15 seconds for post purge. It seems like equipment setup with pre and post purge stay cleaner, less fouling up of the nozzles and flame retention heads.

STEVEusaPA

SuperTech said:

You can't go wrong with either of those controls. With the 4 second delay cord I usually set up the controls for a ten second pre purge, that will give you close enough to the 15 second pre purge typically used. On boilers the thermostat connection is always at the aquastat, TT can be configured "on" with these controls so the burner will fire whenever the aquastat sends 120 volts to it. I often find a jumper wire installed on the TT terminals by guys who don't bother reading instructions.  The only time I have ever had to replace either control is when they have got wet. 

I"ll leave a jumper on T-T for the 70200 in a few situations.
If I want to leave power on while checking something on purging/bleeding the fuel pump. Carlin's only flaw with their primary is if you hold down the reset button, the burner restarts in pump prime mode.
So I can just put my own jumper on T-T to work the burner, then put the little jumper back in when done.
Also helps if you want to pump down the water temperature of the boiler and leave the burner off.

I've asked Carlin to consider switching the pump prime mode sequence because one day, some homeowner is going to think that holding down the reset button until the burner comes on is what to do, then they'll end up pumping 2 minutes of oil into the chamber.

MikeAmann

Location of the ODR sensor -
My house is brick, and my sill plates are sealed and insulated with 4" of Owens Corning PINK rigid foam (R20). I know the sensor is supposed to go on the north side of the house (the boiler is on the south wall), but the easiest way for me to run the wiring is to follow my security system wires up into the attic and over to the soffit where a siren is. Would it be a problem to mount the sensor up that high? 1 story house.

mattmia2

Up high is fine for the outdoor sensor.

EBEBRATT-Ed

North side under the soffett is fine

MikeAmann

I am viewing the Carlin Pro-X and Hydrostat 3250-PLUS videos.
I am In Meriden, CT and both units are made at the C. Cowles & Co. in North Haven, CT.
I like that (right in my backyard) and I now know that both controllers will play well together.
Thanks SuperTech and STEVEusaPA for the great recommendation.

So my previous setup had an Intellidyne IntelliCon HW+ Fuel Economizer connected to the Honeywell aquastat which let me extend running the heating circulator from 200 degrees all the way down to 130 degrees without firing the burner. And I was able to use the aquastat's LO Limit to only allow the IWH circulator to operate above that setpoint (132 degrees = 140 - 8 degree diff for the IWH thermostat). I don't want to send cold(er) water to the IWH than what is already in the tank.

It seems I now have a choice to make in setting the new Hydrostat. I bought the wired ODR to use with it.
The IWH will be wired to ZR and ZC. I see that non-priority mode energizes ZC whenever the LO Limit is reached. And then ZR will fire the burner up to the HI Limit. This is good and as I had it previously.

The video says not to use thermal targeting with a tankless coil. My IWH is essentially a large tankless coil. But the lowest temp thermal targeting will go down to is 145 degrees. That's just a little hotter than how I had it set up previously.

The ODR overrides thermal targeting, and you then use the ECONOMY dial.

If I connect the ODR sensor to WWSD, then I would have both warm weather shut down AND thermal targeting.

How do I set this as a good starting point?

MikeAmann

I am still trying to figure this out.
Because I have a multiple contact relay for the IWH, I was going to wire in the option to interrupt the heating circulator while the IWH is calling for heat. But, to keep things simple, I am not going to do that because I know that this function is already programmable in the Hydrostat with "I" selected. I am hoping that Hydrolevel is way ahead of me and already addressed anything that my mind could dream up. Therefore I will trust them and follow the KISS method.

Here is the dilemna: right now I do not do laundry or shower at the house, so I can just leave the IWH switched off and the tankless coil in the boiler (plumbed after the IWH) satisfies my HW needs. Therefore, HEATING is the priority right now. I do not have to heat the house at all while I am at work, unless we get those sustained really cold temperatures. Then I leave the heat on and set the thermostat to 55 degrees. My pipes freezing is never an issue - I am well insulated in that area.

I am hoping that simply moving the switch from Z (Zone, non-priority) to I (IWH priority) is all I will have to do when I need to use the IWH. But the choice of using ODR, WWSD, and/or thermal targeting still has me confused. Where do I start guys?

I managed to get the Carlin Pro-X Primary control wired and installed on the burner and I ran half of the wiring for the ODR.

--------------------------------------------------------------------------------------

I think I figured out my starting point.
I want IWH priority, so I set the switch to "I" which powers ZC. If switched ON, then a CFH by the IWH thermostat would energize the relay which will run the IWH circulator and energize ZR, firing the burner. If at this time there was a CFH by the heating thermostat, that circulator would be held off until the IWH was satisfied. I guess the LO Limit settting would be what I use to keep "cold" water from going to the IWH coil? I have the IWH thermostat set to 140 degrees and it has an 8 degree DIFF.
So 132 degrees for the LO Limit, correct? BTW, I do have a mixing valve further up the line going to the sinks and bathtub/shower set to 120 degrees. 140 goes to the clothes washer.
Since I have a tankless coil, I should not use thermal targeting. And I would like the water to be able to go below 145 degrees if a lower water temp will meet the heating need. Therefore I would connect the sensor to ODR which overrides thermal targeting, and then I use the ECONOMY dial to adjust the reset curve.
Is it really that easy?

MikeAmann

STEVEusaPA said:

I've asked Carlin to consider switching the pump prime mode sequence because one day, some homeowner is going to think that holding down the reset button until the burner comes on is what to do, then they'll end up pumping 2 minutes of oil into the chamber.

I have been thinking about this. Does this also apply to the "New Generation" units?
When using the 6 wire configuration (has fuel solenoid valve), then it's as easy as keeping VALVE off during purge. Easily done in the software.

STEVEusaPA

MikeAmann said:

STEVEusaPA said:

I've asked Carlin to consider switching the pump prime mode sequence because one day, some homeowner is going to think that holding down the reset button until the burner comes on is what to do, then they'll end up pumping 2 minutes of oil into the chamber.

I have been thinking about this. Does this also apply to the "New Generation" units?
When using the 6 wire configuration (has fuel solenoid valve), then it's as easy as keeping VALVE off during purge. Easily done in the software.

I don't think that is true. Try it. Purge is pre and post purge in your context. Not pump prime mode.

MikeAmann

No, not the blower pre and post purge for airing out the combustion chamber, the purge for bleeding the air from the fuel pump. I was referring to the part about pumping 2 minutes of fuel into the chamber. If the fuel solenoid was closed, then fuel can't spray into the combustion chamber.

STEVEusaPA

The soleniod is energized the entire time during you are in pump prime mode, true of all controls that have it.

MikeAmann

Except for the ODR, I finished wiring the new controls last night. And I didn't make any mistakes!
The wiring is now much simpler than what I had before. Carlin really did think of everything when they designed these controls.




I refilled and bled the air from the boiler and hit the service switch. The Pro-X primary control asked the oil solenoid valve question, I entered YES, and then the start-up sequence initiated. I was trying to bleed the pump of air at this point, but I forgot to turn the valve on, like always. So I got a TFI error (Lockout - No Flame) and the burner didn't fire.
2nd try - with that fault cleared and air bled, the burner fired.
Skipping ahead to the settings, this is what I entered:

• 10 sec - Valve Delay ON (plus the 4 seconds from the delay valve cord equals 14 sec)
  
• 15 sec - Trial for Ignition
  
• 15 sec - Motor Delay OFF
  
• 10 sec - Flame Stabilize
  
• Other 5300 - CAD Ohms Max . . . I might have to change this to Carlin 3300
  
• Interrupted - Ignition Type
  
• NO - TT Jumpered . . . I have the physical jumper installed
  
• Not used - Vent Input
  
• 3 - Allowed Recycles
  

For the Hydrostat 3250-Plus, I set it for these parameters:

• INDIRECT - for zone switch
  
• 200 - HL
  
• 132 - LL
  
• 1 - ECO
  
• ON - Thermal Pre-Purge
  
• F - Fahrenheit
  
• Manual reset - LWCO
  
• A - Circulator on TT call only
  
• ON - Circulator Hold Off
  
• A - for Electro-Well
  
• 10 - High Limit Differential
  

My burner controls and ignitor are now all Carlin. The air tube/nozzle line assembly is Beckett. The only remaining parts that are original Wayne is the burner housing itself and the 1725 rpm motor and oil pump, so I need to follow Beckett SR specs.

I still have to finish connecting the ODR.

While I had the burner removed, I changed the nozzle from .65 to a Delavan .70 x 80A nozzle for a firing rate of .77 with 120 psi. Combustion tests will be in about 1 week. Last time I was a little high on the O2% (6.7), a little low on the CO2% (10.5), and a little too much excess air (47.1) and maybe the stack temperature could be a little higher - all indicating that I am a little underfired (Thanks captainco for that chart you posted).

Below you can see how 3 out of the 4 pairs of air band slots are now blocked off.

MikeAmann

I had my first service call on this tonight.
I got a NO FLAME - LOCKOUT error. I was standing right there to watch it fire up.
The burner is so quiet now that you must be right there to hear it and watch the sequence on the Pro-X primary control. I hit the reset and let it try again. Same. One more time with the viewport open. Looks like no fuel - sputtering, but no flame. The controller says CHECK VALVE and CHECK IGNITION.

Long story short - I tested the oil delay valve with both an ohmmeter and 120 vac. Checks good.
I initiated a sequence to test the ignition. Checks good, strong spark. But before I could get that to happen, the CAD cell was seeing the light in the basement. I had to pull the cell out of the holder to get the sequence to initiate. So CAD cell good.

I attach my old copper oil line to the output of the delay valve, other end in a bottle, initiate a sequence, oil flows just fine. Even with the open line, the gauge reads 115 psi.

Okay, I did just change the nozzle. Could it be clogged in only 1 day? What to do?..... I have the new .70 x 80B solid nozzle that Ed recommended. Okay, let's try that. I flushed the line with carb cleaner again, blew everything out and installed that nozzle.

The burner fired right up and I liked the flame pattern much better. Instead of crawling up the sides of the combustion chamber into the tapered out section at the top of the "bucket", the flame now just completely fills that bucket section. I don't know what the combustion tests will reveal, but I like what I am seeing. YOU WERE RIGHT Ed. Thanks again.

Edit: When I upped the nozzle to .70, I left the air band set to where it was previously with the .65. It will be days until I can borrow the analyzer again, but I did a smoke test and got just the slightest trace - call it a half on the scale (between zero and 1).

MikeAmann

I finished connecting the ODR sensor 2 nights ago. That part works.

Small issue though - The Hydrostat is not seeing the sensor for the LWCO function to work. All the LEDs flash during power-up. The unit is installed on a new electro-well and no teflon tape was used, only Rectorseal. The sensor is fully seated in the well. And the function IS selected in the settings (A for electro-well).
Can an electro-well be bad? Do I have a bad sensor? Or is it the Hydrostat itself. I hope not because I would rather not unwire it. It took a long time to get the wires to lay in the housing nicely.

I called Hydrostat and have not gotten an answer. I sent an email - nothing there either. Do I need to contact SupplyHouse? Hydrostat / Carlin is located in North Haven, CT - I am only 2 towns away in Meriden. I can drive to them if necessary.

EdTheHeaterMan

I was never a fan of the Hydrolevel aquastat with LWCO built in. Just like I was never a fan of the R8182D Trippleaquastat-protectorelay. Put too many things in one box and if one fails then you need to replace it with the expensive "Do All" part. I have found that the Trippleaquastat-Protectorelay can be replaced with a Carlin 70200 and a L7224U for less money than the OEM part.

What happens when the LWCO fails and you just switch the control to "Electrowell Sensor NO". The heat is on but there is no LWCO anymore. Can we depend on the consumer to insist on having a replacement control or an additional separate LWCO be added?

Just my thoughts, We all have opinions on the best way to do stuff.

Mr.Ed

SuperTech

Your issue could be related to grounding.  Usually with aquastats like the 3250+ or the aquasmart I will see a ground wire from the aquastat to somewhere on the boiler itself.  Usually with Peerless boilers it is connected to the studs for the flue connector on the top of the boiler. 

MikeAmann

SuperTech - thanks, I thought of that, but my wiring has the separate ground wire, the pipes are copper and grounded, and anywhere where something non-metal interrupts that path (water filter) has a ground wire to keep the electrical path. But I can double-check the grounding of the electro-well with a meter - simple enough. I sent a message to SupplyHouse because Hydrostat is not returning my call or email.
I purposely bought Carlin / Hydrostat because they are less than a half-hour drive from me.

Edit: the ground at the electro-well is perfect, as I thought.
SupplyHouse got back to me and they are sending a replacement Hydrostat 3250-PLUS and new electro-well.
I will swap the sensor first. If that does not get the LWCO function working, then the Hydrostat will be next, and then finally the electro-well. I hope it's just the sensor.

MikeAmann

It wasn't the sensor. So I started looking at the difference between the standard well and the electro-well. With the electro-well, the center copper tube is electrically isolated from the brass nut - the standard well has no isolation. I inserted a wire into the electro-well and did an ohms check to the nut - zero ohms - dead short. What the heck? Is it even possible for an electro-well be shorted? I removed the well, cleaned it off, and retested it - open circuit - the short is gone. What the heck? I looked in the hole where it screws in and I see a shiny spot on a fin of the tankless coil. There's the short.
The new electro-well is exactly the same length as the old standard well, so that was also pushing on the tankless coil all of these years.

So I used a stone wheel to carefully grind the fins down a little. But the well still bottomed out when I tried it again. What to do? I had a nylon bushing that I turned into a cap and glued it onto the end of the well with Plumber's GOOP. Then I put about 8 wraps of teflon tape on the threads of the electro-well. The instructions say NO TEFLON TAPE, but I did an ohms check on the controller from the case ground connection to the metal tab that locks down to retain the Hydrostat to the electro-well. It is connected. So the NO TEFLON TAPE thing is not absolutely necessary for this function to operate - it's just added insurance. I did check that the nut threads were in fact grounded - they are.

I reinstalled the electro-well adding a little Rectorseal #5. An ohms check said open circuit - no short anymore. I put everything back together and now he LWCO function is operating as it should.

I was going to get my snowblower ready, but maybe I can do the (hopefully) final combustion analysis tonight instead.

MikeAmann

Well my repair didn't last very long. The tankless coil must move around a little during heating and cooling because the LWCO LED is out again. The fins must have rubbed through the nylon. I will have to get a shorter electro-well.

MikeAmann

I was at FW Webb today to buy a .65x80B and .65x70A nozzle and I was asking about the shorter electro-wells. Someone there made a great suggestion to simply remove an inch from the electro-well sensing bulb and either silver solder or braze the closed end back on. I love this idea and I am fully capable of doing this modification.