Universal Oil Water Boiler Aquastat Relay for Boilers with and without Tankless Coil

It is very difficult to answer Honeywell/Resideo questions definitively. Especially if you are not on site. Controls sold to boiler manufacturers as OEM components will frequently have unique model numbers, typically the last four digits referred to as the back up number. Typically, the exact model number you are trying to replace is only available from the boiler manufacturer as a replacement part. For example, based on a Google search is suspect your control came off a boiler produced by Peerless. To know if anything is unique about that control you would need to contact the boiler manufacturer. They will know about the operation cascade of that specific boiler based on the model and serial number. This universal triple acting aqua stat has a high limit, low limit and (circulator) relay. The low limit can be turned on or off, so it will work on cold start boiler or ones with tankless coil. The relay can be used to operate a single circulator or act as an end switch in a system that has multiple circulators or zone valves. In the years this universal control has been available I have not run into a residential forced hot water oil fired boiler where I have not been able to use it and to configure it to work as a replacement for the control on the boiler. But every hydronic heating system is different, so to do this you need a working understanding of the system’s wiring logic. If not, you should leave it to a local qualified licensed professional. So, is it a direct replacement? No. I would consider a “direct replacement” to be the same in every way. This control is a universal control that requires experience and knowledge to be configured correctly and integrated into the system.

If you scroll down the Home Depot product listing page you will come to a section entitled Product Details. If you expand that section, there are PDFs of the product documents. If you open the specification sheet you will find table 2 which lists the different part numbers for sensor probes in the following lengths which can be ordered separately. 12”,18”,24”,36”,48”

Resideo provides a one-year warranty on this and similar controls

I am not sure I completely understand your question. If I go to a job site to diagnose a lack of hot water the first thing, I want to do is determine why the problem exists. It could be the aqua stat, but it could just as likely be one of the other system components. As to which one I can’t tell you because I do not know your system, and every system is different. You are welcome to give me a call and we can have a conversation about your specific system. I have done this for a long time and may be able to send you in the right direction. Aqua stats typically just fail, and the system stops working altogether. It would not be typical for them to create the problem you describe. It could happen but I doubt it. As to replacing an aqua stat, you can go by the model number or cross it to one that does the same thing. But that requires an understanding of the total system. Chris 978 651 3301

Scroll down the product listing page to the area entitled Product Details where you will find PDF’s of product documents. If you open up the specification sheet you will find traditional two wire thermostat wiring on page 8. I believe page 9 covers what you are looking for. Depending on what thermostat you are using you may want to give Honeywell now known as Resideo a call. I know people who have been able to get some advanced thermostats to work and I know others that have had to resort to using a device called a common maker to simulate a common.

Without looking at the specific boiler and system in question it is hard to be definitive. However as a general rule this universal triple acting aqua stat is a good replacement for most oil boiler double and triple acting aqua stats.

No this aqua stat was not specifically manufactured to be the direct replacement of the number you reference. Although it could be used as a suitable replacement. I cannot give you a definitive answer as I don’t know what boiler you have and even you did I would need to be on site. Allow me to explain as it may help. The L7224 in the beginning of the long model number indicates the series and what this is; an aqua-stat. So to that extent they are the same. The C1004 also called the backup number indicates the way the control was configured. My guess is that this control was configured for a specific boiler manufacturer. Based on my searches I would assume Peerless. Therefore the connections and orientation have been designed to be what that manufacture wanted. This new control has a backup number of U1002. The “U” designates universal. This control is designed to replace many. It has functions that can be turned on and off so it can be configured in the field to work in many situations. I am confident it has the capability to replace your control. But it will not be exactly the same. The terminals may be in different locations and be indicated differently. It is important that you have a working knowledge of the logic designed into the wiring schematic so you can wire it correctly. Also that that you read and understand the instructions so that you can set the control parameters correctly so that it performs the same functions as the control you are replacing. For example you need to set the high limit temperature, set the low limit temperature or possibly shut off the low limit if this is a cold start system, etc.