Honeywell Aqualink centralized electric heat

[goldstar]

I have a customer who lives in a house that has all electric 240V baseboard heat. Whoever built this house, in their infinite wisdom, decided to use low voltage thermostats wired back to a bank of switching controls. The brand name on the control is Honeywell Aqualink but I don't believe they make this equipment anymore so I'm trying to find a replacement. There are 2 separate 5-zone switching enclosures located adjacent to the main breaker panel and there are 8 separate 20 amp, 240V circuits used for the heating units. There's also a 24v transformer built into each switching unit. After doing some investigating I found that each of the heating zones has one side of the 240V circuit wired directly to it and the other side switched through one s/p zone of the control (I know it sounds weird but please bear with me). When a zone calls for heat, 24VAC is sent to a carbon resistor of a specific zone. When that resistor heats up it heats up a spring-loaded contact (similar to a reed switch) that will close when hot, sending the second phase of the circuit to the heating unit. When the temp in the room is satisfied the 24VAC is removed, the resistor cools down and the circuit opens. Some of these zones have now locked up and heat all the time, thus my reason for finding replacement controls.

As far as I can tell these units work similar to Jandy pool controls. I would use a Jandy control but my only concern is that the small relays wouldn't handle the current load required by the baseboard heating units. I'm thinking of building my own switching controls by using Potter-Brumfield heavy duty (25 amp rated) 2-pole relays w/ 24V coils. If anyone has a better idea or knows of control equipment I can use would you please point me in the right direction ?

Thanks

 

[stickboy1375]

Just install normal Electric heat relays....

 

[texie]

I have a customer who lives in a house that has all electric 240V baseboard heat. Whoever built this house, in their infinite wisdom, decided to use low voltage thermostats wired back to a bank of switching controls. The brand name on the control is Honeywell Aqualink but I don't believe they make this equipment anymore so I'm trying to find a replacement. There are 2 separate 5-zone switching enclosures located adjacent to the main breaker panel and there are 8 separate 20 amp, 240V circuits used for the heating units. There's also a 24v transformer built into each switching unit. After doing some investigating I found that each of the heating zones has one side of the 240V circuit wired directly to it and the other side switched through one s/p zone of the control (I know it sounds weird but please bear with me). When a zone calls for heat, 24VAC is sent to a carbon resistor of a specific zone. When that resistor heats up it heats up a spring-loaded contact (similar to a reed switch) that will close when hot, sending the second phase of the circuit to the heating unit. When the temp in the room is satisfied the 24VAC is removed, the resistor cools down and the circuit opens. Some of these zones have now locked up and heat all the time, thus my reason for finding replacement controls.

As far as I can tell these units work similar to Jandy pool controls. I would use a Jandy control but my only concern is that the small relays wouldn't handle the current load required by the baseboard heating units. I'm thinking of building my own switching controls by using Potter-Brumfield heavy duty (25 amp rated) 2-pole relays w/ 24V coils. If anyone has a better idea or knows of control equipment I can use would you please point me in the right direction ?

Thanks

The resistor arrangment sounds like some kind of heat anticipater circuit. Also, are you sure that this controller also is not doing some kind of demand management, which used to be pretty common with electric heat in some areas? I would be carefull as to the relay you use as noise can be an issue from the high number of on/off cycles and also is hard on contacts. I would suggest a relay like an Aube RC840 which is dead quite and made for this type of duty and will last.

 

[goldstar]

Thanks Stickboy and Texie. Both are good suggestions. I think the electric heat relay might work the best with the current situation. I just don't like one phase of the 240V being present at the baseboard heat at all times but they've lived with it this long so I may not change it.

 

[stickboy1375]

Thanks Stickboy and Texie. Both are good suggestions. I think the electric heat relay might work the best with the current situation. I just don't like one phase of the 240V being present at the baseboard heat at all times but they've lived with it this long so I may not change it.

You could buy two circuit relays, but a waste of money in my opinion.

 

[ActionDave]

I just don't like one phase of the 240V being present at the baseboard heat at all times but they've lived with it this long so I may not change it.

I wouldn't worry about it. The way I see it, one phase is present all the time most everywhere electricity is used in the house.

 

[goldstar]

Just took a closer look at the Aube RC840T and it looks like a neater product and less expensive than the Honeywell unit. Thanks Texie.

 

[stickboy1375]

Just took a closer look at the Aube RC840T and it looks like a neater product and less expensive than the Honeywell unit. Thanks Texie.

.............

 

[iwire]

Any real reason for not just getting Honeywell replacements?

 

[texie]

Just took a closer look at the Aube RC840T and it looks like a neater product and less expensive than the Honeywell unit. Thanks Texie.

Interestingly, Aube is owned by Honeywell. I think it was originally a Canadian company they bought some time back. I like the Aube relay for resistance heat because it is encapsulated and silent. Over the years I've found that there are a lot of Canadian electric products for heating applications that are handy. They must use a lot of electric heat up there. You could also consider Aube solid state relays. Also they make some very good thermostats for baseboard heat and also for elec. floor heat.

 

[Rampage_Rick]

I've found that there are a lot of Canadian electric products for heating applications that are handy. They must use a lot of electric heat up there.

It's all the cheap hydroelectric power. Up until a decade ago we had a special tariff here in BC for electric heat called "E-Plus." Basically you had a second meter base solely for electric heat, and the cost per kWh was about half the regular rate. The downside was there were provisions for turning off the cheaper meter during peak grid loading (though there was no practical system in place to do so) and homeowners were required to maintain a suitable supply of "alternate" heating fuel (usually firewood)

It was discontinued several years back, but I believe there may be a handful of people still grandfathered in.

 

[goldstar]

Any real reason for not just getting Honeywell replacements?

I've researched this and I don't believe they make direct replacement parts for these units. I figure if I'm going to repair 1 or 2 zones I might as well upgrade the whole system with quality products.

 

[goldstar]

It's all the cheap hydroelectric power. Up until a decade ago we had a special tariff here in BC for electric heat called "E-Plus." Basically you had a second meter base solely for electric heat, and the cost per kWh was about half the regular rate. The downside was there were provisions for turning off the cheaper meter during peak grid loading (though there was no practical system in place to do so) and homeowners were required to maintain a suitable supply of "alternate" heating fuel (usually firewood)

It was discontinued several years back, but I believe there may be a handful of people still grandfathered in.

We've had the similar set ups down here with electric water heaters. There was usually a time clock located inside the premises that would heat the water during off-peak hours. I occasionally come across these when I do service upgrades.

 

[iwire]

upgrade the whole system with quality products.

Well that was why I asked as Honneywell makes great products, seems a shame to remove it.

But I can't say if they have a direct replacement for your application or not.

 

[kwired]

24VAC is sent to a carbon resistor of a specific zone. When that resistor heats up it heats up a spring-loaded contact (similar to a reed switch) that will close when hot,

This is no different than the "sequencing" relays used in electric furnaces except they don't incorporate a 24 volt transformer into the relay assembly.

I don't see a real good need for the timed delay it will provide with a baseboard heater. On a forced air system it can allow for preheating before starting the blower. They are quieter than a magnetic contactor Other than those possible benefits they are just high maintenance items from my experiences. I often replace them with a regular contactor. Some units do just use contactors instead of the "sequencer" anyway.

If I were in your shoes I would probably use contactors and a master 24 volt supply.

 

[goldstar]

This is no different than the "sequencing" relays used in electric furnaces except they don't incorporate a 24 volt transformer into the relay assembly.

I don't see a real good need for the timed delay it will provide with a baseboard heater. On a forced air system it can allow for preheating before starting the blower. They are quieter than a magnetic contactor Other than those possible benefits they are just high maintenance items from my experiences. I often replace them with a regular contactor. Some units do just use contactors instead of the "sequencer" anyway.

If I were in your shoes I would probably use contactors and a master 24 volt supply.

I've already done that in one section of the house but was hesitant to do that here because of available space. If I can figure out a way to get (10) 2-pole contactors in that space I'll consider your suggestion. Thanks.

 

[texie]

I've researched this and I don't believe they make direct replacement parts for these units. I figure if I'm going to repair 1 or 2 zones I might as well upgrade the whole system with quality products.

You might want to confirm that there was no demand control as part of your old system. In some areas it used to be common for the POCO to offer a "demand" rate for electric heat customers. For the customer to benefit, and not end up being penalized by the rate, they needed a demand controller. We still have such systems in our area.

 

[iwire]

They are quieter than a magnetic contactor

IMO That is the reason for using them in this application.

I often replace them with a regular contactor. Some units do just use contactors instead of the "sequencer" anyway.

I would never do that in a dwelling unit and I suspect that is what he is dealing with.

 

[goldstar]

You might want to confirm that there was no demand control as part of your old system. In some areas it used to be common for the POCO to offer a "demand" rate for electric heat customers. For the customer to benefit, and not end up being penalized by the rate, they needed a demand controller. We still have such systems in our area.

Not sure what I'd be looking for other than a separate meter and this house only has one. Can you be more specific ?

 

[goldstar]

Well that was why I asked as Honneywell makes great products, seems a shame to remove it.

But I can't say if they have a direct replacement for your application or not.

I think I'll be OK with the Aube heat relay. It looks like a quality product and has an "active" indicator light. Besides, I believe thay're owned by Honeywell.