Utica Oil Boiler Configuration Question

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Old 12-22-16, 01:51 PM
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Utica Oil Boiler Configuration Question

Hi all,

We just moved into a house that has a Utica Starfire 3 Oil Boiler feeding baseboard hot water heat. The boiler also provides hot water that is mixed before feeding to an electric hot water heater. I had the boiler serviced yesterday after moving in, and the tech told me that he didn't think my system was configured in the most efficient way and he suggested a change.

The boiler has 4 zones with separate circulators. One zone is controlled by a Honeywell relay on the side of the boiler which has the aquastat (set to 160 deg low, 180 deg high, 10 deg offset), and then there are 3 separate Honeywell relays for the other three zones. He pointed out that these relays are unable to call for heat and just start their separate circulators.

He then suggested replacing the relays with a 4 zone Taco relay board so that all zones would be able to call for heat (but leaving the relay that has the aqua stat in it), and then this would allow us to set the low point much lower (he suggested 110 deg, which looks like it is the lowest setting on the Aquastat; I don't recall if he suggested lowering the high point as well) and save significant fuel (especially in the summer when all the boiler is doing is providing preheated water to the electric hot water heater so anything over 120 is unnecessary; I asked about just turning the boiler off in the summer and he suggested against it saying it could cause leaks in the boiler).

I had another contractor out to get a second opinion today, and he said he understood where the first guy was coming from but wasn't sure that it would save us enough money to make it worth the costs of the work, he also wasn't sure that 110 deg was warm enough to prevent leaking. As a side note, he also pointed out that the boiler is probably oversized and would typically be intended for a house about twice the size of ours. Note that unlike the first person who was a service technician, this guy was a salesman.

Does anybody have any suggestions about what the best path is here (do what the first guy suggested, do nothing as the second guy was leaning towards, or some other solution)? Trying to learn as much as I can about the system as well, as I had a heat pump in my previous house so I am completely unfamiliar with boilers. Another piece of info that may be relevant is that I am also planning to replace the old school Honeywell T87 thermostats with Ecobee3 stats.

Thanks for any help anybody can provide!
 
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  #2  
Old 12-22-16, 02:31 PM
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What is the model number of the Honeywell relays that he says doesn't start the boiler on a call for heat.

If you don't care about the preheated domestic water you can turn your boiler into a cold start in the winter instead of running to maintain temp. Depending what your fuel costs are it may be worth it.
 
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Old 12-22-16, 03:45 PM
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Thanks for the response!

Each is an RA89A of varying age.

When you say convert to a cold start, do you just mean drop the low limit to the min (110 in this case) or a more substantial change?
 
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Old 12-23-16, 07:10 PM
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Unfortunately the 89A is not the right relay for your job. You can buy the right ones or go with the Taco zone relay control. You can get the number of zones you need in on control to simplify things.

The cold start I mentioned is eliminating your low limit and having your boiler run on demand instead of running to maintain temp. It would only run on a call for heat. Depending what model aquastat you have.
 
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Old 12-23-16, 07:36 PM
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Thanks for responding again!

What do you mean by "You can get the number of zones you need in on control to simplify things."?

The aquastat model is Honeywell L8124.

Both companies that I had out mentioned that they don't recommend letting the boiler go completely cold because it is not designed for cold start and that it could lead to leaking from expansion/contraction. Do you think that is a false worry and not something to be concerned with? I am not at all opposed to just using the electric hot water heater for domestic hot water. It was actually installed brand new by the sellers of the house just a few weeks ago because the old one died just prior to sale. But I wouldn't want to do anything that would compromise the integrity of the boiler.
 
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Old 12-23-16, 09:47 PM
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What I meant by the number of zones is Taco makes a switching relay controls that will accomadate anywhere from a single zone to a 6 zone panel all in one panel.

If you go to SupplyHouse.com and click on heating and then switching relays and then Taco you can see what's available. You can also check out your other controls.

When you find what you want scroll down to installation instructions and it will show you all the wiring and other info on the product.

As far as shutting boilers down for the summer there are different opinions. The way I look at is if your boiler didn't come with a coil, and less and less are today, because they're just not efficient what would you do with the boiler in the summer.

Gas boilers today do not come with tankless coil heaters so you either get an indirect or a separate tank. With a separate tank I'm sure they're not running them in the summer.

When I had a separate tank mine was off all summer with no problems but gaskets wear after a while so nothing is carved in stone but gaskets are replaceable.
 
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Old 12-23-16, 11:31 PM
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The Burnham I've been working on was wired like yours... one zone was wired to the circulator output of the aquastat, the other zones were on separate honeywell relays (R845A's).

The relay outputs on our system were hardwired to the "blue" input side of the aquastat... i don't think the aquastat was really meant to operate that way. Last year the relay in the aquastat fried... not sure if its because there was 120v back-feeding it... Either way it is bypassed now, and I installed a taco 4 zone relay (SR504) from ebay to replace all the relays.

It doesn't save any money on efficiency, but, well, it turns on when calling for heat now, so there's that, and it is a much cleaner installation... every tech that comes out understands it at a glance instead of scratching their heads for half an hour (when the relay fried last year, the emergency tech solved it with a pair of wire cutters... snipped out the controls for 2 of the zones, hopefully that won't happen again)

Next week I'm adding a tekmar outdoor reset to get some more efficiency out of the system... the honeywell aquastats might be good at keeping the boiler from exploding, but they suck at saving oil.

I'm rambling, but I would say that adding a multi-zone control (taco is the most common i've seen, so that's what i used) and an outdoor reset to boost your efficiency (tekmar is the most frequently recommended on here) would be a solid investment in both reliability and oil savings.

Honestly its too bad the seller put in an electric water heater... direct oil-fired water heaters are about the fastest, most efficient water heater options available, and electricity is pricey!
 

Last edited by vilord; 12-23-16 at 11:48 PM.
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Old 12-24-16, 12:05 AM
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As for running your starfire 3 as a cold start boiler, that boiler was sold as both a cold start water heating only boiler and as a hot start boiler with a tankless coil...

So as spott said there's a chance you might need to change a gasket, but that boiler is certainly capable of being run cold start
 
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Old 12-27-16, 12:39 PM
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vilord,

Thanks so much for your input! I am especially intrigued by the option of changing the boiler to a cold start.

I have a wiring question for anybody who can help, as I am planning to install an SR504 myself. Does this link - https://www.taco-hvac.com/uploads/Fi...4(102-084).pdf - show the proper way to wire the SR504 to the aquastat (for both tankless coil and cold start configurations)? Currently, the thermostat that can fire the boiler is connected to the T/T connections on the aqua stat, the aquastat is wired to the circulator for that thermostat's zone, and the ZC and ZR connections on the aquastat are unused. Am I correct that in the new configuration (for tankless coil), the aquastat's ZC and ZR terminals would be connected to the SR504 as shown in that PDF and the aquastat's thermostat and circulator terminals would no longer be used?

I've attached a picture of my current aquastat wiring if that helps.
Thanks!
 
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Last edited by ForTheGlory; 12-27-16 at 03:18 PM.
  #10  
Old 12-27-16, 07:32 PM
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FTG,
Yes, you will follow the diagram for the tankless operation until you do go cold start. That will keep your low limit operating for hot water.

Your ZC, zone control, & ZR, zone relay terminals should have been used if they would have used the right relays (RA845) initially, which would have turned your boiler and pump on on a call for heat from any zone instead of just the pump. It was just a matter of the wrong relays being used and someone not knowing what they were doing with the wiring.

Since your boiler is going to be operating anyway you might as well use your coil and then shut it down in the summer if you want.
 
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Old 12-28-16, 05:15 AM
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Thanks spott!

Anothee question, can I safely use the old Honeywell thermostats with the Taco relay board R/W connections (they currently hook up to T/T terminals on the RA89As and Aquastat) as an interim step before installing my new ecobee3 thermostats? That way I can verify I hooked up the relay board correctly before proceeding with the thermostat change.
 
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Old 12-28-16, 10:11 AM
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FTG,
Yes you can connect them to the tstat terminals on the 504.
 
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