instant water heater issues

[ModSquad]

Hey guy's,

I know some of you are very familiar with different aspects so I thought I'd throw this out.

I got a tankless water heater setup.. it's an electric unit. my problem is I've got my in floor heat all setup and bled, but when I go to turn the unit on, the pilot light doesnt come on. I've read the manual and all it says is make sure it's connected to a 60Amp breaker and that the pressure going in is 40 to 45PSI. This is how I have it setup.

I've traced the power, the unit is getting the 240 volts..

 

[ModSquad]

so the unit is getting power.. basically it's like it's not getting pressure? system is set to 42PSI. book says it needs between 42 and 45. I checked the connections(hard to explain), but if I manually connect the elements, it heats up fine.. not sure what to think here..

 

[ModSquad]

k, upon further investigation, the flow meter on the heater is not detecting enough flow to turn the unit on.. now to figure out what's causing that..

 

[5wndwcpe]

I think your thermostat is not calling for heat. This is what should turn your circulating pump on to create flow which will in turn fire your heater.

 

[ModSquad]

no thermostat yet. pump is turned on with the breaker.. testing.. I was gonna hook up the thermostat after..

 

[ModSquad]

turns out that the pump doesn't have enough flow to activate the water heater..,.

 

[Nosman]

What pump and heater are you using?

 

[ModSquad]

Taco 007-f5 pump and a JC1 JCE-55 water heater.

Specs on the heater are as follows
This uses 220 voltage, 20 - 50 amp and regular 3/8-inch pipe thread connections.
It's 11 000 watts power and can deliver 2.5 us gallons of water per minute in continuous flow
Suitable water pressure of 40 to 45 psi
You can set the temp of the water to up to 165 F
It has an energy efficiency of 96 % !!!
It measures 10 x 7 x 5 inches.

garage is 24x22 with 10 Ft ceilings.

 

[Nosman]

Oddly enough that is the exact same heater I am using right now. That pump may not be enough to activate that heater with the heater's flow control at full. I've found so far that I have to have the valve at just past the second position for the heater to stay on. That being said, I run mine on 15min on, and then 1 hr 15min off cycles, and the garage is toasty at about 60 degrees right now, with outside temps in the -8C range.

 

[ModSquad]

ok great.. finally I found someone using the same or similar unit. so it would be flow related...

What size pump are you using? and at what pressure are you running your system at?

Are you using a thermostat to cycle the heater or are you using a relay or something?

 

[Nosman]

The Grundfos pump I'm using appears to be a little stronger than your Taco, but I can't find exact flow figures. Mine is currently runnig at about 12-15 psi, any higher seemed to slow things down a bit.
As for firing the pump, it took me a while to figure out how I wanted to do it and my current configuration might not be the last. i decided not to run it off of the thermostat for a couple of reasons. The main one is this, if the thermostat called for heat at let's say 57 degrees, it would fire the pump/heater and not shut it off until it reached 59 degrees. Beacause the in floor systems are fairly slow to react due to the mass of concrete, it may end up fired for too long and end up overshooting temp wise. The thermostat I have is completely programmable with two external temp resets, but the time and money invested in sensors and setup time made me shy away from that.
I decided to use something I had laying around, luckily. I have an old IBM Home Director setup that came with my computer years ago. It allows me to automate the heater/pump by firing it at scheduled times, it's rather slick. I have it programmed for the 15 min on, and 1:15 off cycles, and it actually sends a digital signal from my computer , through the garage wiring, and into a module that I have plugged in to a garage outlet. The module then fires the pump which is plugged into it.
Be careful and pull the cover off of your heater and see how many of the legs of the element fire when you turn your pump on, that may give you a better idea of what's happening. Let me know if you have any more questions, I'd be happy to fire off some pics or info for you.

 

[Franz©]

First, I believe there is a problem with the internal switching of the instant water heater sensing sufficient flow to trigger the heating coil. Since the heater will burn itself up almost instantly from insuficient flow the internal flow switch is probably built the way it is for a reason. The trick will be finding a way to either accomodate that switch or bypass it in a safe manner that would prevent burnout if no flow was present.

Then again, I always wanted to set up my hydronic system in a manner that employed a small processor to sense outside ambient temperature, wind direction and speed as well as time of day for greater efficiency. Unfortunately the cost savings potential never justified the cost of Johnson Controls sensors.

 

[ModSquad]

that sounds like a slick unit you got going there. hehe.. unfortunatly I don't have anything like that lying around, but I'm sure i can figure something out.

yeah, I was running at 40PSI cause that's what the unit calls for, but after some playing around, dropped the pressure to around there. 12 -15 and it seems to flow better for sure..

right now it's on a 60Amp breaker, but I'm going to be swapping that for a 30Amp as only 2 legs are firing as I only have it set on the #1 setting and probably won't need it any higher. It still gets pretty damn hot tho.. I did notice that my pilot light doesn't go on... I'm gonna flush the system again 1 more time cause I think there's air in there somewhere and that might be causing issues..

Which Grundfos pump are you using? I have another one here (Bell & Gossett) an it's slightly larger so I'm gonna swap it back in. if you have pics of your setup that wouldbe great. How many feet of tubing are you using? also, what size? I'm running 600ft of 1/2" PEX. and I got about 8 to 10Ft of 1/2" pipe outside the floor. my manifold is made of 3/4" copper T's that neck down to 1/2"connectors for the PEX. Also the Manifold is fed by the 1/2" Galv pipe I ran for the rest of the system..

 

[Nosman]

I am running 600 ft of 3/4", with about 15' running outside to the entry by the door. The reason you don't get the light on is because the leg of the heater that triggers the light isn't made, not a big deal. You could attach it to one that is if you wanted to. If you have a computer out there and are at all interested in my setup I'll provide you with a link, it's not too pricey.
Oh and try dropping the pressure a little more and see if it makes a difference. The pump I'm using is a Grundfos UPS15-58FC 3 speed, on high.

http://cgi.ebay.ca/IBM-75H8381-Home...ryZ50584QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
This is the exact kit I have. The parts can be had separately if needed.

 

[ModSquad]

cool thanks.. that alone might make the difference... your running 3/4" tube which can handle 4GPM which the 1/2" can only handle 1.5GPM. the heater can handle 2.5GPM continuous, but how much flow does it need to activate the switch. hehe.. I'm gonna drop the pressure a bit more tomorrow, and flush the system again to make sure there is no air.

I am interested on your setup.. it seems like it would be more efficient then running it off a thermostat.. less wasted running time. if you got a link shoot it over. I do have a pc in the garage. that's for the link on Ebay..

 

[ModSquad]

well I got it up and running.. just changed a few things and rerouted some lines and installed a electric tank heater as I already had it and didn't have the funds for a new pump. seems the electric needs a much larger flow to function properly. I'll drain, reinstall and troubleshoot more this summer.. Need the heat now as it's getting cold..

Thanks for your help and input guys.

 

[Northstar9126]

Why does a water heater calling for 240V have a pilot light?

 

[ModSquad]

it was an instant water heater. the pilot light just indicated that the unit was running or not. just a visual gauge. I still think that these units would be more efficient then a full tank water heater as there is no wasted energy. and you only need the unit connected to either a 20 or 30 Amp circuit.

 

[wmonroe]

If you don't mind me asking what model electric tankless heater did you get and how much did it cost? I have a 50 gallon tank heater now because i needed to get the heat on so nothing froze but I'm thinking the tankless would heat faster with less wasted energy. (Oh and gas isn't an option in my garage thanks to the township)
Will

 

[Nosman]

It's a JC1 JCE55 heater, I have the same one, as we were discussing in earlier posts. 11.000 watts, or less if you set the temp lower, and it works great especially for the price. I paid about $142 for mine last year and I see they are still available for about the same price.

 

[ModSquad]

yup, exactly as he mentioned. the only thing is you need a larger pump.. which Nosman mentioned in an earlier pump. I just don't have the $$ for the pump right now as the pump I have now was free and so was the 50 Gal water heater.. so I just isntalled in for this winter cause it's getting cold and I'm worried about freezing, and I'll flush and reinstall and troubleshoot this summer when I have more time and hopefully $$ saved up for a better pump.

I paid 130$ for my JC1 unit. the only thing is the company is obsolete so there is no support for it.. However there are tons of spare elements for sale on Ebay for cheap.

 

[wmonroe]

ModSquad- How is the 50 gallon tank heater doing compared to the tankless?

Nosman- Thanks for the info on the heater.

Will

 

[ModSquad]

well I never got to run the tankless for a long time cause I didn't have enough flow in the system to activate it. I need a bigger pump.

From what I could tell when I was flushing the system and noticed it was purged, I turned the breaker on to the heater to see how it would work, and seems to work great with the proper flow. I will be gettign a new pump this coming summer and setting the instant heater back up for next winter.. at least I'll have a comparison of the 2 winters.. but for now, the regular tank water heater seems to be working fine.. it's -20 celcius outside last couple days and the garage is running about 15* no problems.. the water heater hasn't had time to catch up yet tho. I filled it and turned it on and started circulating water immediatly.

Noted also, I just noticed the tank heater is not designed for space heating, so I think it's the way the elements are setup. if you are going to use a tank heater, check and make sure it's designed for commercial/residential or indicates good for space heating.. I'll see how it works for now, but It should be caught up by now.