Hayward heater with Variable Speed Pump

[ncnmra]

We recently moved to a (new to us) home with a pool. The pool equiment is quite old and I'm in the process of upgrading it. I have replaced the old pump with a Hayward MaxFlo 500 VSP, which is great (albeit louder than I expected).

I'm now in the process of having the heater replaced with an H300FDN. I'm quite surprised actually that it appears that the heater has NO output to indicate that it is heating and/or "call for heat" style thermostat function. I wanted to use this to trigger the pump to run at a higher speed.

Does anyone know how to achieve this? I'm an electronics engineer and have a few ideas, but I hope I'm missing something simple?

 

[Jimrahbe]

n,

Welcome to TFP... a great place to find the answers to all your "Why did my baggage go to the other London?" questions...

Most heater are designed so that they can be externally controlled, but not so that they can control other things. I took a quick look at the manual and don't see anything obvious that could trigger the pump.. If the pump is running at an RPM that does not close the pressure switch then none of the series of things that need to happen to turn the heater on will happen.. If the pump is already running fast enough to turn on the pressure switch, then there is no reason to increase your pump speed.

I guess you could tap into the thermostat board, but that would take some of your electronics training to figure out.

Please let us know how you do it, as it might help others with the same issue.

We have some great heater guys here at TFP, so let's see if we can get some of the them to chime in...

Thanks,

Jim R.

 

[kefjens]

I have a h250fdn that I would like to be able to read remotely. It is not worth $800 like the heater reader setup costs so if you come up with a way let us know! Also, maybe the heater reader does what you want, I quit looking at it when I saw the cost.

 

[ncnmra]

Thanks for the response guys! I feared that it wouldn't be an easy answer. I also saw the Heater Reader and I'm not thrilled by the price. I think I can whip something together like this:
https://hackaday.com/2018/06/07/wifi-pool-controller-only-cost-20/

It sort of shocks me that the heater doesn't have an output showing that it "wants to heat", which I could use to just trigger a higher speed on the VSP. It seems to me that any external controller would require its own temperature sensor which is frustrating since the heater already has one (or more!).

Initially I was thinking that I'd just monitor the current of the fan for instance to trigger the pump to a higher speed, but I agree with Jimrahbe that if the pump is running too slowly, it may not trigger the control board to activate the heat cycle.

On a similar question then, what is the typical speed (rpm) that the heater needs to run? I like to run my VSP 24/7 and I just throttle it down during on-peak hours.

 

[Jimrahbe]

n,

The speed to close the heater's pressure switch really depends on how your individual pool is plumbed, but generally I believe it will run between 1500 and 1800 RPM...

Let's see if some of our members can chime in with their RPMs for heater operation..

Thanks,

Jim R.

 

[sktn77a]

"If the pump is running at an RPM that does not close the pressure switch then none of the series of things that need to happen to turn the heater on will happen.. If the pump is already running fast enough to turn on the pressure switch, then there is no reason to increase your pump speed."

Therein lies the problem. Nothing you can tap into on the heater board to increase flow rate will be active because the flow switch needs to be closed first.

 

[ncnmra]

Therein lies the problem. Nothing you can tap into on the heater board to increase flow rate will be active because the flow switch needs to be closed first.

Agreed.....unless there is some trigger signal somewhere which is likely a) hard to find b) not trivial to interface with and c) wouldn't be condoned by Hayward to begin with. Curiosity has the better of me now though so once its installed I will likely poke around with a meter/scope.

 

[jimmythegreek]

you could look for a used or cheap aqua plus/pro logic unit and use that for automation, I have a raypac 266btu and it turns it on and off however I see fit. I can have the pump at 1200rpm for making chlorine and then heater wants to run it bumps it to 2100 rpm automatically. There is a device that is like a relay that senses voltage and kicks a sperate circuit off, if you have 4 speed terminals on that pump you may be able to make the heater be a trigger to a relay circuit, I beleive they have AC/DC relays. The hayward heater must have some sort of control board to be used w their automation. I can look into it a bit for you but you would need to post the links to the manuals for your specific pump and heater.

 

[PoolGate]

You are going at this backwards. Automation exists to do what you want. The heater is not the automation it is controlled by the automation.

 

[ncnmra]

you could look for a used or cheap aqua plus/pro logic unit and use that for automation, I have a raypac 266btu and it turns it on and off however I see fit. I can have the pump at 1200rpm for making chlorine and then heater wants to run it bumps it to 2100 rpm automatically. There is a device that is like a relay that senses voltage and kicks a sperate circuit off, if you have 4 speed terminals on that pump you may be able to make the heater be a trigger to a relay circuit, I beleive they have AC/DC relays. The hayward heater must have some sort of control board to be used w their automation. I can look into it a bit for you but you would need to post the links to the manuals for your specific pump and heater.

I finally have my heater and system all setup, and yes, now I'm looking to automate it better. I like the idea of the "HeaterReader", but not the price. I realize rolling my own solution will likely cost more, but there is something more satisfying about it.

It appears that my heater needs about 2300rpm to kick on the flow sensor. My pump usually runs at 1250rpm during the day ("on-peak") times.

My heater is a Hayward H300:
https://www.hayward-pool.ca/assets/documents/pools/pdf/manuals/Manual225.pdf

My Pump is a Hayware MaxFlo VS 500:
https://www.hayward-pool.ca/assets/documents/pools/pdf/manuals/can-maxflo-vs-IS23520VSP.pdf


I know that the pump has relay inputs to control the pump at various speeds. I just don't know what signal I could take off the heater to kick it up. I believe when there is low flow, there won't be any signal at all.

You are going at this backwards. Automation exists to do what you want. The heater is not the automation it is controlled by the automation.

Yes, I do agree and understand. The issue is that most of the automation is astronomically priced, and usually lacking. Additionally, I'd prefer not to have to install additional temperature sensors for the automation. The heater already has an inlet temperature sensor, and that's all I'd need really. Besides, there is a huge level of satisfaction to doing this kind of thing youself

I'm working on a concept for a HeaterReader type product. That thing would be appealing at $200 or so, but I'm not really interested at $800.

 

[randytsuch]

I have an ESP running espeasy. The ESP connects to some relays that control the speed of my hayward vsp.
You should be able to control the heater with a relay too, to turn it on and off.

So, instead of asking the heater to be the brains, turn the heater into a dumb device. Use the ESP to turn on the heater, and then change the pump speed when the heater is on.

espeasy is rather limited, and it would be difficult to do this with just an esp.

I'm also running Home Assistant on a pi. I use HA to tell the esp when to turn on and off the pool pump.
You can wire an temp sensor to the esp, so you would also have the water temperature. I use a ds18b20, cheap one from china that comes encased in a metal cylinder so its protected.

Obviously a non trivial solution that will take a fair amount of work, but out of pocket cost will be fairly low.
I don't do this because I rarely heat the pool (don't need to), so if I want the pool heated, I just go turn on the heater, and manually set the pump speed.

But I do have my esp turning on the pool pump, based on what HA tells it to do.
One side benefit is this would be the start of a "smart home", HA is really capable of doing a lot, and supports a bunch of devices.

Randy

 

[ncnmra]

I have an ESP running espeasy. The ESP connects to some relays that control the speed of my hayward vsp.
You should be able to control the heater with a relay too, to turn it on and off.

So, instead of asking the heater to be the brains, turn the heater into a dumb device. Use the ESP to turn on the heater, and then change the pump speed when the heater is on.

espeasy is rather limited, and it would be difficult to do this with just an esp.

I'm also running Home Assistant on a pi. I use HA to tell the esp when to turn on and off the pool pump.
You can wire an temp sensor to the esp, so you would also have the water temperature. I use a ds18b20, cheap one from china that comes encased in a metal cylinder so its protected.

Obviously a non trivial solution that will take a fair amount of work, but out of pocket cost will be fairly low.
I don't do this because I rarely heat the pool (don't need to), so if I want the pool heated, I just go turn on the heater, and manually set the pump speed.

But I do have my esp turning on the pool pump, based on what HA tells it to do.
One side benefit is this would be the start of a "smart home", HA is really capable of doing a lot, and supports a bunch of devices.

Randy

YES! You read my mind exactly. I was thinking of going down the ESP route, we use them for projects at work. I actually found a cute setup with a display:
http://m5stack.com/

I think you can buy modules with relay outputs, etc. Because my setup is indoors, I think this would work well, and yes, I was going to use a DS18B20 to get the temperatures of incoming, outgoing and air temperatures. A guy on Hackster did something like this:
https://www.hackster.io/mmackes/pool-controller-8dfa69

I think it would be a fun project. I wonder if there would be a market for something like this? Again, the Heater Reader seems to sort of do the same thing, but I don't think it is attractively priced.

 

[randytsuch]

Here's some info on my setup, but this writeup is dated. For instance, my temp sensor stopped working, so I recently replaced with one already encased. Also changed sw from domotiz to home assistant. But it will give you some ideas.
link

I stuck my setup in a sprinkler box because the box had a built in ac outlet. I plug in a usb cube into the outlet, and that provides power for the esp and relays.

But if I did it again, I'd probably buy a 115vac to 5vdc converter, and stick it all in a weatherproof plastic box.

Randy

 

[Martyd]

n,

Welcome to TFP... a great place to find the answers to all your "Why did my baggage go to the other London?" questions...

Most heater are designed so that they can be externally controlled, but not so that they can control other things. I took a quick look at the manual and don't see anything obvious that could trigger the pump.. If the pump is running at an RPM that does not close the pressure switch then none of the series of things that need to happen to turn the heater on will happen.. If the pump is already running fast enough to turn on the pressure switch, then there is no reason to increase your pump speed.

I guess you could tap into the thermostat board, but that would take some of your electronics training to figure out.

Please let us know how you do it, as it might help others with the same issue.

We have some great heater guys here at TFP, so let's see if we can get some of the them to chime in...

Thanks,

Jim R.

Can you tap into the gas valve switch? You would also have to program a delay at the end of the heating cycle. I would also like to have the heater trigger the pump to run at a higher speed during heating.