Aquasmart Lockout & converting to coldstart- Can't afford $6k/yr oil bill!

[Cold in PA]

As my username suggests- we are cold in PA. Our oil provides heat and hot water to a 2400 sq ft house and the bill is roughly $6000 per year. We can't afford to heat the house any longer- it's about $750-800 every 5/6 weeks, 3 seasons a year and the summer is not much better. After some research I realized we have a few problems...
-I think the boiler is oversized. My husband made these exact boilers at a previous job and this is one of the biggest ones he seen.
- The basement is always VERY warm, the warmest room in the house, even with a window that is always open (no glass, husband has had it on the to do list for years). Despite this, basement is a sauna all year. So, we are producing the heat but it's just not reaching the upstairs.
-Lastly the boiler is a hot start system. Unfortunately it is also a tankless coil. I would like to convert it to a coldstart and add an indirect tank, so I was running a test by disabling the low limit on the Beckett aquasmart and calling for heat from the thermostat to see whether or not the boiler will leak while frequently starting from low temperatures. This leads me to my latest problem…
- Ever since starting this cold start test, the relief valve has been pouring out water when starting from cold temperatures.
-Even more confusing is that the Beckett Aquasmart has now started to malfunction. It is reading "lockout cancel". Per the manual this means the cancel button was held for longer than five seconds..but the cancel button was never held. Sometimes the Aquasmart stays locked out for hours on end and then all of a sudden comes back on for about 2 to 3 seconds and then dies, reading "lock out cancel". When it starts to cycle of on and off, it will do this indefinitely until I disable the burner.

Good news however, the boiler itself has not yet leaked so there is hope and converting our existing boiler, Peerless EC4, to a coldstart. If anyone has any insight please let me know. We have electric heaters going for now and the baby is bundled up, but I need to get figured out ASAP. I plan to call HVAC tech tomorrow but would like some information to go on first...thanks in advance!

 

[Dana]

Were had you previously set the low-limit on the AquaSmart? If it's a cold startable boiler you can usually set the low-limit a bit lower than 140F, as long as there's a stainless liner for the flue rather than terra-cotta lined masonry. (Of course a model name & number never hurts when trying to figure this stuff out online.)

What are your electric rates? What is your local oil pricing?

If you're on a regular oil fill-up service that stamps a "K-factor" on the slips, what is your ZIP code (for design temp purposes- the first three digits is fine if you don't care to share)? With a midwinter K-factor and a ZIP code it's possible to get a good estimate of the actual heat load. Otherwise, a few wintertime fillups with the EXACT dates and quantities it could be derived from weather data (with a ZIP code, of course.) Thermostat settings would also improve the accuracy. If you prefer to run the numbers yourself, try this method.

Unless this an insulated brick or stone house with single-pane windows (no storms) even the smallest oil boilers are oversized, but with the AquaSmart and a suitably low low-limit (140F is standard for oil), it'll come close to hitting it's AFUE despite that at an oversizing factor of 3x or so, but at 6x it may be just too much. Any uninsulated heating system plumbing should be insulated with at least 1" thick fiberglass pipe insulation to reduce standby & distribution losses, but there's not much to do about jacket losses other than lower the boiler temperature.

 

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[Cold in PA]

Hi Dana! Thank you for responding- not only to me, but all the others you have helped through this forum. I have spent a solid 20 hours plus learning about boiler heat systems before posting and your name consistently came up on here. I don't necessarily need to become an expert on this, but I want to have a little more than basic knowledge in order to make educated decisions moving forward.

Good point, I should've mentioned we are in a stone house with 1 foot walls and storm windows. Another important factor- Last winter we closed the upstairs living quarters so that we only had to heat the downstairs- 1200 square foot space. So that $6k was to heat 1200sq feet and limited hot water usage. I also have a strict 65° thermostat rule so I can say for certain that's the highest it was all winter (hubby tries to sneak it to 80, yes 80, but I was always able to turn it back down quickly) On top of which, we spent a good amount of time away from home visiting family last year so that the house was unoccupied overall about 3 months over the course of a year. In the winter I set the thermostat to the bare minimum of 50° to keep the pipes from freezing but was shocked to find I still needed frequent fill-ups.

I can also say for certain, the oil fill ups were every six weeks exact to the day unless there was guests and then it was every 5 weeks. And I let the tank run to empty... I know, tsk tsk. But, because of that bad habit, I can say without checking that every fill up was 218 gallons. The first three digits of our zip are 194.. I attempted the k factor on my own, but the possibility of having more than one degree day within a single 24 hr period is not clicking for me.

Electric is .06/kilowatt. Oil is average 2.99/gallon, but upon checking around, some companies are already up to 3.54/gallon. I was thinking of a hybrid heat pump hot water tank instead of indirect tank to save oil, but with boiler running constantly (hot start) not sure if that would save $$.

Low limit was previously 160.. Stayed home and with NO heat calls on the boiler (thermostat off, no hot water used) boiler fired 12 times in 24/hrs. That's when I disabled the low limit. The boiler is a peerless EC4 and has been hot start for approx 7 years (installed five yrs before we moved in), which is why I was worried about gasket/ seal leaks since the boiler is accustomed to high heat. After turning the low limit off, I left the house for a few days to cool the boiler completely. When I came back, initially the cold start test went well- no leaking from seals despite repeated calls and moderate cooling in between. However now the Beckett Aquastart is reading "Lockout cancel"- the error goes away when "enter" is pushed, but quickly returns if boiler is cool. Yesterday I cleared the error and immediately put a call on the boiler, which seemed to help because the Aquasmart functioned for hours until we stopped putting calls on the heat after which it read lockout again. This error started AFTER disabling low limit, so it seems either there is a problem inside the boiler or the aquastat does not like being a coldstart unit.

Good info on insulation- speaking of the pipes, some of what in think are delivery pipes look too small compared to what I've seen in repair videos. Most of the pipes coming out of the boiler or half-inch the exception of one that is 1 1/4 inch.

 

[Cold in PA]

Some photos of boiler/Aquasmart

 

[Dana]

With six cent electricity and three dollar oil heating water with a plain old electric tank is cheaper than with oil, even with an indirect. Before spending money on a heat pump water heater, spending it on a cold-climate mini-split heat pump would be a better investment, and with 6 cent electricity would pay for it self in short years. (If you'd like me to run those numbers for you I will.)

With an indoor temp of 65F the load calculation would be done using base 60F data, but if the house wasn't continuously occupied and set down to 50F while away for days/weeks at a time between fill ups that would skew the numbers (a lot). For an outside design temp using Philly's +15F is close enough, even though your 99th percentile outside design temperature may be a degree (two at most) cooler than that. (Allentown's is +10F). The generic outside design temp for Montgomery county is +14F, though there is some variation within the county. See:

https://articles.extension.org/sites/default/files/7. Outdoor_Design_Conditions_508.pdf

https://www.energystar.gov/ia/partn... Temperature Reference Guide - 2015-06-24.pdf

The pipes in the pics all look like 3/4" to me, which is common for systems using baseboard convectors. If broken into zones it's common enough for the zone plumbing to be half-inch.

How much, and what type of heat emitter do you have (zone by zone)?

A boiler with a DOE output of 181,000 BTU/hr (yes, it's huge for a house that size) needs at least 360' of typical fin-tube baseboard to balance the rate heat is coming out of the baseboards with the heat being put into the system by the boiler. With out sufficient radiation or without enough thermal mass the burner is going to short-cycle. Ideally the AquaSmart would be able to suppress that a bit, but to do it really well it needs to be programmed with a large difference between the high limit and low limit numbers. If short-cycling it'll knock ~10% off the AFUE lost to pre-purge and startup cycles. If radiators, estimate the square feet EDR (per zone).

With the low-limit set to 160F the standby losses are huge. Start by setting the low limit to 140F and the low limit differential to 5F. Does it still deliver enough hot water? If yes, leave it there for now. The high limit can be set to 200F with a high limit differential of 50F for now. The big differential on the high-limit allows the thermal mass of the boiler & system to drop a full 50F without firing the burner during a call for heat, maximizing the lengths of the burns, minimizing the number of cycles. The overall average temperature of the boiler will be somewhere in-between, and the controller's algorithms will try to lower the average temp.

 

[Dana]

BTW: I haven't dug up an online manual for the EC4 yet, but on the nameplate pic it looks like it can be down-fired with a 1.25gph nozzle and 150,000 BTU/hr output, instead of the 1.5 gph/181,000 BTU/hr output. If you're currently running the 1.5 gph nozzle it's worth swapping in the 1.25 gph to lower the oversizing factor, increasing the minimum burn time, lowering the number of burns per season/year, all of which helps average efficiency.

If the foundation mortar is in good shape it's possible to insulate the foundation with a couple inches of closed cell spray polyurethane painted with an intumescent paint (for fire safety) or a steel studwall set an inch in front of the foundation with 1.5-2" of foil facedrigid polyisocynurate foam board covered with half-inch wallboard. (If rigid foam, air tightness is critical to getting the full performance out of it.) Even though it's not living space, if the boiler room is the warmest room in the house (probably is, and still would be even with pipe insulation), even at 50F basement temps the heat losses to the outdoors are high (particularly above-grade) with a stone foundation. While insulating the walls in the living space would be good too, that normally requires a major gutting of the living space to do, and costs a lot more.

At some point it's worth considering that step, but is secondary to the low hanging fruit of getting the best efficiency out of the AquaSmart/Peerless, and way behind installing a ductless mini-split heat pump.

The short math on it is that even best-case the Peerless is going to deliver 115,000 BTU/gallon into the heating system, a better class cold climate ductless will deliver at least 10,000 BTU/kwh. So it takes 11.5 kwh to be the heating equivalent of a gallon of oil. With 6 cent electricity the that's the equivalent of ~69-70 cent/gallon oil. At 12 cents it' the equivalent of $1.40 oil. A 1-ton cold climate ductless runs ~$3500-4000 (installed, all-in) in my neighborhood, and delivers about 16,000 BTU/hr or more at your +14F outside design temp, even more when it's warmer.

Verify what your electricity pricing is, fully delivered (not just energy pricing)- take the total bill, divide by the kwh. Check also if there is a rate change above some particular amount of electricity use, and what that is. But even at 24 cents/kwh it's still slightly cheaper to heat with ductless heat pumps than $3 oil, and there's essentially no standby or distribution loss sending heat where it isn't needed.

 

[Cold in PA]

BTW: I haven't dug up an online manual for the EC4 yet, but on the nameplate pic it looks like it can be down-fired with a 1.25gph nozzle and 150,000 BTU/hr output, instead of the 1.5 gph/181,000 BTU/hr output. If you're currently running the 1.5 gph nozzle it's worth swapping in the 1.25 gph to lower the oversizing factor, increasing the minimum burn time, lowering the number of burns per season/year, all of which helps average efficiency.

If the foundation mortar is in good shape it's possible to insulate the foundation with a couple inches of closed cell spray polyurethane painted with an intumescent paint (for fire safety) or a steel studwall set an inch in front of the foundation with 1.5-2" of foil facedrigid polyisocynurate foam board covered with half-inch wallboard. (If rigid foam, air tightness is critical to getting the full performance out of it.) Even though it's not living space, if the boiler room is the warmest room in the house (probably is, and still would be even with pipe insulation), even at 50F basement temps the heat losses to the outdoors are high (particularly above-grade) with a stone foundation. While insulating the walls in the living space would be good too, that normally requires a major gutting of the living space to do, and costs a lot more.

At some point it's worth considering that step, but is secondary to the low hanging fruit of getting the best efficiency out of the AquaSmart/Peerless, and way behind installing a ductless mini-split heat pump.

The short math on it is that even best-case the Peerless is going to deliver 115,000 BTU/gallon into the heating system, a better class cold climate ductless will deliver at least 10,000 BTU/kwh. So it takes 11.5 kwh to be the heating equivalent of a gallon of oil. With 6 cent electricity the that's the equivalent of ~69-70 cent/gallon oil. At 12 cents it' the equivalent of $1.40 oil. A 1-ton cold climate ductless runs ~$3500-4000 (installed, all-in) in my neighborhood, and delivers about 16,000 BTU/hr or more at your +14F outside design temp, even more when it's warmer.

Verify what your electricity pricing is, fully delivered (not just energy pricing)- take the total bill, divide by the kwh. Check also if there is a rate change above some particular amount of electricity use, and what that is. But even at 24 cents/kwh it's still slightly cheaper to heat with ductless heat pumps than $3 oil, and there's essentially no standby or distribution loss sending heat where it isn't needed.

Hi Dana,

I just wanted to thank you for your help and give an update. The past few months have been difficult with some health issues in the family, but we recently were able to get working on our heating situation once again.

Per your recommendation, we’ve seriously considered a mini split heat pump. A Mitsubishi (sp?) was installed at our last home to supplement the wood stove. It worked VERY well, especially given the fact that our previous house had very little insulation. Ideally we would like to install the same type of mini split in this home, but I see two challenges- one, the floor plan is the farthest thing from “open concept” Despite being a one room schoolhouse 100 years ago, both floors have been significantly blocked in since with about 10 rooms total. Second challenge are the plaster covered 1.5 foot thick stone walls. From what I remember about the mini split installation, the copper pipe needs to go through the wall into the interior. I’m not sure that would be possible with our walls. I read many sources that say old stone homes should avoid drilling holes and if it’s absolutely necessary, to rather chisel out larger stones and then fill back in around the pipe. *I’d be really interested to hear if in all your experience you’ve ever heard of placing a mini split outdoors and running the piping straight through into the basement (there are already access points on ground level) and then continuing the pipes up through the house indoors?* I.e.. as opposed to running pipe straight up the side of the house exterior. There are already exposed water pipes running vertically inside the home and I don’t see an issue adding one more.

The second possible solution i’ve Been researching is an Electro Electric Boiler. Specifically EB-MX-20. I saw you mention the company on an older thread and it got me thinking. I’m about to contact the company with some questions. I can’t figure out by reading their site if electric boilers are hot start or cold start ...or if that even applies.

Also, we recently installed a heat pump water heater with a $500 state rebate. Total for the unit was $800 plus installation. This measure hasn’t put a dent in our oil bill, but we’ll be able to shut off the boiler come summer and switch the the hot water tank, which should save some. I know we talked about heating bills before, thank you for breaking down the numbers! That was so helpful. We recently got another oil bill- every five weeks like clockwork! The furnace was set to 60 degrees plus space heaters running. Luckily the cost of oil went down and the total fill up was $550. The cost is still considerable however, seeing how it’s every five weeks WITH the added electric due to space heaters running.

We have a lot to consider here. Thanks again for your help....I’m learning more about heating systems than I ever wanted to!

Emily

 

[Reach4]

Electric is .06/kilowatt.

Before computing with that number, study your bill. There may be an electricity charge of $0.06, but there may be a non-fixed delivery charge of $0.05 per kWh. Then on top of that may be other charges based on the kWh usage. Then a sales tax based on the total bill including the variable charges.

There could even be a demand charge based on your highest use, and good luck figuring that one out.

 

[Dana]

In most cases running the refrigerant lines through the pre-existing penetrations of the basement would work. There are limitations on the total refrigerant line lengths though, beyond which the capacity of the heads need to be derated. Mitsubishi makes branch boxes to help with that, but it adds to the complexity. One key thing to figure out is where the vertical chases would be for running refrigerant lines to a second or third story. Sometimes plumbing stack chases can do double-duty. The other issue is to figure out is condensate drainage/management during the cooling season.

If there is a full basement to work with it may be worth considering 1-2 ducted mini-splits to deal with the fact that it's been broken up into many rooms. Fujitsu makes a nice series of mini-ducted mini-splits that put the competition to shame in terms of air-handler power (for a mini-duct cassette) and heating capacity at low outdoor temperatures. A 1.5 ton -18RLFCD delivers about 19,000 BTU/hr at -5F, and about 22,000 BTU/hr @ +20F, yet can still throttle back to 3ooo BTU/hr @ +47F. Mitsubishi doesn't really have anything like it, though they do have cold-climate multi-zone compressors that can take bigger (but non-modulating) air handlers. Multi-zone compressors don't really modulate the individual zones with load, which makes them a less attractive solution than fully modulating single zone systems.

To really do this right requires a room-by-room heating/cooling load calculation (ACCA Manual-J method or similar.)