Girrard Tankless Hot Water Heater

[Vmsuper]

I just installed 2nd Gen Girrard Tankless hot water heater. When I cycle and turn on the unit at the LCD panel or at the outside master switch, the fan turns on and, then the burner ingnites for just a couple of seconds then goes out. When we open any faucet on the hot water side at any loaction in the RV the heater will not ignite.

[TheDustyGeek]

We just had a crash course last weekend with our new rig which has the same GSWH-2. The conclusions I came to are:

1) Set the water temp on the control panel to 110F
2) Just use the hot water, with no or extremely little cold water mixed in. Use the control panel to adjust the temperature.
3) It’s all about the water flow. If the flow rate is sufficient, the water heater fires off. Too little flow and it shuts off or never starts.
4) Really COLD water coming in may affect the output temperature. Slowing down the flow (closing the hot on the fixture) a tiny bit can take care of that as it allows the water to be in the heat exchanger just a little longer. See #3.
5) It doesn’t work without LP. Should be self explanatory, but our LP gauge was reading full - turns out the gauge wasn’t installed properly so the gauge wasn’t tracking the float position like it should. The real clue there was when the furnace wasn’t working either. [emoji17]I carefully popped the gauge off, used a magnet to adjust it down to E, and it fortunately synced up when we filled it on the way home.

If it never fires off when your hot is wide open and there are no codes on the control panel, it’s possible the flow sensor (a little propeller in the water line inside the heater) is bad, has debris jammed in it, or there’s indeed too little flow (really low water pressure?). To help confirm the latter, try adding water to your fresh tank and using your pump, or if doing that already, using city water. Is your system in Winterize mode or water heater bypassed - you can confirm that by pulling on the T&P valve in the water heater.

[Vmsuper]

Thank you, Ill try the 110° setting as well as the holding tank with the pump to see if its a low water pressure issue. I am running off of my well system, yet believe we do have over the 45 psi in water pressure.

[paulwadley]

The DustyGeek is correct about the tankless system. Water flow needs to be at least 55psi to operate correctly. I have an adjustable water pressure regulator that I use when on City water to be sure it is not too high or low. If the pressure is too low, I switch to my tank water supply and use my onboard water pump. If it is too high I can adjust it at the water pressure regulator. To check your propane, try turning on a burner on the stove to see if it lights and is a blue flame in case your propane gauge is malfunctioning and not showing a correct level. I set our temp to 106 and leave it. No cold water is used while in the shower.

Paul

[Vmsuper]

I have 60 PSi after the sediment filter, so my water pressure is adequate and above the called for 55psi, Im going to next try adding an integral regulator, thus eliminating the trailers factory regulator and the adjustable high pressure regulator at the propane tank. (120gl) Possibly the WC is to low and the heater is shutting down when calling for propane.

[Chateau_Nomad]

We have the "old fashioned" 6 gallon tank. We boondock a lot, and need to conserve water. I have a "trickle method" rinsing soap off of dishes with hot water, which works great. Is this even possible with a tankless... considering the flow volume that's needed? Sounds like a tankless is better suited for using a water hookup with endless supply and decent pressure. Am I missing something?

[DavidEM]

Originally Posted by Chateau_Nomad

We have the "old fashioned" 6 gallon tank. We boondock a lot, and need to conserve water. I have a "trickle method" rinsing soap off of dishes with hot water, which works great. Is this even possible with a tankless... considering the flow volume that's needed? Sounds like a tankless is better suited for using a water hookup with endless supply and decent pressure. Am I missing something?

Yes, you are correct. You can't trickle rinse dishes with hot water using the Girard tankless water heater. The burner won't come on with low flow.

BTW, as an engineer I am a little troubled by the 55 psi requirement. The actual requirement for the Girard's burner to come on is 0.8 gpm. Yes 55 psi usually provides 0.8 gpm, but not always. Depends on the fixture and how far it is from the water heater.

David

[Scubawise]

If we trickle the hot water the tankless kicks on and we have showered when outside temp is 35 and hot water works great

[yukongrant]

Originally Posted by Chateau_Nomad

Am I missing something?

It's my understanding the water pressure ENTERING the hot water heater has to be at least 45 psi. It does not matter how much water is exiting the heater. I've used the trickle method and like Scubawise, it works for me.
The big change using on demand hot water - never mix it with cold water. There's no need to mix. It takes a bit to get used to. But if you don't mix, you'll have a lot fewer problems.
When I owned a 6 gallon heater, I could get up to 10 gallons of hot water by mixing cold with the extremely hot from the tank. But that was all. I had to wait for the next tank of hot water. But with a tankless, there is no limit.
Someone on this forum changed my opinion of water hook ups with a tankless. Because water pressure will vary from place to place, he simply fills his fresh water tank and always uses the pump. He know the pump produces the correct pressure to work and just doesn't even fiddle with the hook up. That makes sense to me. I'll be trying that this summer.

[Chateau_Nomad]

So... what's with the flow rate requirement? Seems if you trickle from a tap in the RV (in my case much less than 1/2 gal./min.) it wouldn't be enough flow to trip the burner according to mfg. specs.?? BTW, we both take Navy showers... so the 6 gallons is plenty for two showers... especially with a 10 minute break between.

Right now no plans on switching RVs... just want to edumacate myself in case of a tank failure - replace situation... or that impulse RV "upgrade".

[Scubawise]

Originally Posted by yukongrant

It's my understanding the water pressure ENTERING the hot water heater has to be at least 45 psi. It does not matter how much water is exiting the heater. I've used the trickle method and like Scubawise, it works for me.
The big change using on demand hot water - never mix it with cold water. There's no need to mix. It takes a bit to get used to. But if you don't mix, you'll have a lot fewer problems.
When I owned a 6 gallon heater, I could get up to 10 gallons of hot water by mixing cold with the extremely hot from the tank. But that was all. I had to wait for the next tank of hot water. But with a tankless, there is no limit.
Someone on this forum changed my opinion of water hook ups with a tankless. Because water pressure will vary from place to place, he simply fills his fresh water tank and always uses the pump. He know the pump produces the correct pressure to work and just doesn't even fiddle with the hook up. That makes sense to me. I'll be trying that this summer.

90% of the time we fill fresh water tank and shower

[yukongrant]

Originally Posted by Chateau_Nomad

So... what's with the flow rate requirement?

You are correct. It makes no sense. But my manual says:

The Water Control Valve of the GSWH-2 provides good control of the outlet temperature within a wide range of inlet water temperatures as are normally encountered in Recreational Vehicles. The unit is shipped with the Water Control Valve set at fully open/maximum flow. If desired, the operating flow can be manually adjusted. It is located on the rear of the water heater.
In case of operation with extreme cold inlet water temperatures (approximately less than 45°(F) the performance of the Water Control Valve can be optimized by adjusting the flow as shown in Figure 8 below.
NOTE - This also can be accomplished by adjusting the hot water flow at the faucet.

I added the emphasis to the last line. I have no idea why it works this way. But in our experience, it does work like this.

[alajeu]

After much trial and error we finally got used to using the Gerard Tankless heater by keeping the temp adjusted to 120 and keeping it there. We don't use city water because it is too cold coming out of the ground even in the hot summers. Use your onboard tank after the water has had time to heat up to "room temperature" and use your pump to keep the flow adequate.


Alajeu

[Jess737]

I've had a bunch of weird water issues. Our tankless heater comes on just fine but will not reach the selected temperature most of the time. If I turned down the hot side valve in the shower toward off the temperature would get higher, nice but I sacrificed pressure. Then if I plugged a couple holes on the shower head the temperature went up and of course got higher water pressure. Our water supply is from city water. About once every 2 weeks or so the water just stops flowing out the faucets. I checked our hose and the city outlet and water flowed just fine. Connected everything again pressure regulator said 50psi, but still no water. The next day we had water. Then a few days later no water. Everything looked good outside. Went back inside and only the cold water flowed out when turning on the right(cold valve on faucet). Tried getting hot water and nothing. Didn't even activate the blower on the water heater. As for the shower....no water at all. I then removed the pressure regulator attached to the spigot and turned the water on but no water at all again. Later that day we had water, but at a much higher pressure coming out of sink and shower. The tankless heater only gave us 92* out of kitchen sink and 82* out of the shower. I plugged the holes again in the shower head and water temperature went up to a nice hot temperature but I had to shield my valuables. Any ideas on what is going on with our water system would be much appreciated.

[Frank@theShop]

Originally Posted by Vmsuper

I just installed 2nd Gen Girrard Tankless hot water heater. When I cycle and turn on the unit at the LCD panel or at the outside master switch, the fan turns on and, then the burner ingnites for just a couple of seconds then goes out. When we open any faucet on the hot water side at any loaction in the RV the heater will not ignite.

How is the water pressure at the faucet? Make sure you have sufficient water pressure. If the water pressure is low, it will not trigger the burner to ignite. Keep in mind that the burner is only designed to turn on when you turn on a faucet. That is why these units use so little propane. When running on the on board tank it is sometimes necessary to adjust the pressure at the pump if it is too low. Sometimes city water connections might experience water pressure that is too low for the Girard to light during peak hours. Depending on the unit and design of the plumbing system on a particular unit, turning on the pump while on city water will "boost" low city water pressure.

[16ACE27]

Originally Posted by Frank@theShop

How is the water pressure at the faucet? Make sure you have sufficient water pressure. If the water pressure is low, it will not trigger the burner to ignite. Keep in mind that the burner is only designed to turn on when you turn on a faucet. That is why these units use so little propane. When running on the on board tank it is sometimes necessary to adjust the pressure at the pump if it is too low. Sometimes city water connections might experience water pressure that is too low for the Girard to light during peak hours. Depending on the unit and design of the plumbing system on a particular unit, turning on the pump while on city water will "boost" low city water pressure.

You're replying to someone who hasn't been on the Forum for almost a year (since his last post in this thread). Good info though.

[16ACE27]

Originally Posted by Jess737

I've had a bunch of weird water issues. Our tankless heater comes on just fine but will not reach the selected temperature most of the time. If I turned down the hot side valve in the shower toward off the temperature would get higher, nice but I sacrificed pressure. Then if I plugged a couple holes on the shower head the temperature went up and of course got higher water pressure. Our water supply is from city water. About once every 2 weeks or so the water just stops flowing out the faucets. I checked our hose and the city outlet and water flowed just fine. Connected everything again pressure regulator said 50psi, but still no water. The next day we had water. Then a few days later no water. Everything looked good outside. Went back inside and only the cold water flowed out when turning on the right(cold valve on faucet). Tried getting hot water and nothing. Didn't even activate the blower on the water heater. As for the shower....no water at all. I then removed the pressure regulator attached to the spigot and turned the water on but no water at all again. Later that day we had water, but at a much higher pressure coming out of sink and shower. The tankless heater only gave us 92* out of kitchen sink and 82* out of the shower. I plugged the holes again in the shower head and water temperature went up to a nice hot temperature but I had to shield my valuables. Any ideas on what is going on with our water system would be much appreciated.

Most people that run this tankless units turn the temperature down so that they have full hot water running at a comfortable shower temperature with no cold mixed in.

You can raise the temperature for dish washing if you like.

[Frank@theShop]

Originally Posted by 16ACE27

You're replying to someone who hasn't been on the Forum for almost a year (since his last post in this thread). Good info though.

Whoa! I did indeed. Not sure how that happened, lol. I clicked on the "new posts" in the upper right menu bar and that is where I read the post. Weird.

[16ACE27]

Originally Posted by Frank@theShop

Whoa! I did indeed. Not sure how that happened, lol. I clicked on the "new posts" in the upper right menu bar and that is where I read the post. Weird.

It was in your "New Posts" because Jess737 posted in the thread yesterday.