Girard On Demand Water Heater Question

[wifi_guy]

Hi all. First time out in our 22 Fuzion 428.

Not on shore water, running off our fresh water and water pump. Hot water works for the shower. Will not work with the faucets. WILL work however with multiple faucets on. Turn one of the other faucets off and loose hot water again.

What am I missing here? Please save me! LOL

[JRTJH]

There is a "flow valve" that will not turn on the water heater until a specific flow rate is going through the valve. Your statement that it will not work with a single faucet on but does work with multiple faucets is the "giveaway"...

There should be an adjustment to lower the "trigger point" on the valve in your owner's manual. Here is a link to page 9 in the troubleshooting manual. The sensor adjustment is circled in the lower right photo. Make sure it is fully open.

Essentially, if you turn on HOT water only, there should be enough flow to trigger the water heater. If you mix water (hot and cold) at the faucet, you'll be reducing the flow through the water heater and cause it to shut down.

Tankless water heaters are great "when they are adjusted correctly and the water temperature remains constant" and they can be a "royal PITA" when flow rates, water temperature, water pressure fluctuate.

You might try using only hot water at the faucet and possibly remove the diffuser/aerator from the faucet to increase water flow if the sensor valve won't open enough to trigger the water heater with your "low flow at the faucet"....

When you take it in for service, be sure to identify the issue with your dealership. They should be able to adjust it properly if you can't.

[wifi_guy]

Originally Posted by JRTJH

There is a "flow valve" that will not turn on the water heater until a specific flow rate is going through the valve. Your statement that it will not work with a single faucet on but does work with multiple faucets is the "giveaway"...

There should be an adjustment to lower the "trigger point" on the valve in your owner's manual. Here is a link to page 9 in the troubleshooting manual. The sensor adjustment is circled in the lower right photo. Make sure it is fully open.

Essentially, if you turn on HOT water only, there should be enough flow to trigger the water heater. If you mix water (hot and cold) at the faucet, you'll be reducing the flow through the water heater and cause it to shut down.

Tankless water heaters are great "when they are adjusted correctly and the water temperature remains constant" and they can be a "royal PITA" when flow rates, water temperature, water pressure fluctuate.

You might try using only hot water at the faucet and possibly remove the diffuser/aerator from the faucet to increase water flow if the sensor valve won't open enough to trigger the water heater with your "low flow at the faucet"....

When you take it in for service, be sure to identify the issue with your dealership. They should be able to adjust it properly if you can't.

Thanks, that was my next step. Getting to that knob is a pain but I'll try and open up things later and do some adjusting.

So in reading what that knob does, do you think this is an issue of that knob not being fully opened? From factory it should have come that way. Or is this an issue of I need to close it off a bit? I would think I need to open it up more so that allow more volume through the valve so the sensor sees more water going through it?

Maybe I am over analyzing things. I'll first see if the valve is open all the way like it should have come from factory and go from there.

The challenging part, with this camper is I don't have an external fresh water fill. So getting more water in my fresh water tank is going to be difficult. I'll figure out something there as well.

[JRTJH]

Opening the valve to "full open" will give you maximum water flow capability through the water heater, BUT it will not "fix your low flow faucet flow"...

The water heater works, not on "heating water when you turn on a faucet" but works to "modulate gas flow to the burner to prevent burning up the water heater while maintaining a "heating capacity" (gas flow modulation) that is safe for the heater while allowing enough BTU's to the burner to raise the cold water temperature....

The two stage valve (27K/34K BTU) is based on water flow/water temperature.

If your faucet does not allow the minimum flow through the faucet, there's nothing to adjust on the water heater.... Your statement that it works fine with 2 faucets turned on is an indicator that the flow sensor/valve is not sensing adequate flow with 1 faucet open.... If adjusting that valve doesn't solve the problem, and removing the faucet aerators doesn't solve the problem, but it works with 2 faucets turned on, it's definitely a flow problem. Possibly a bad sensor in the water heater, but equally possible is the reality that your faucets may not support enough water flow to turn on the water heater....

Did it ever work properly ??? If it did, first clean the faucet aerators (they'll restrict water flow) and then focus on the water heater.....

[wifi_guy]

We just got the camper.

I’ll first try taking out the areator from a faucet. If that doesn’t help i’ll try the valve.

Shower worked great this morning.

[JRTJH]

Completely remove the faucet aerator and see if it works. If it does, then try cleaning the aerator because there is a significant amount of "construction debris" in the water tank/plumbing runs to block water flow through the aerator. This "fact of life with any RV" is the compelling reason to install a strainer on the inlet side of your water pump. Sucking up plastic drill shards from the fresh water tank is one of the primary reasons why water pumps fail.

If that doesn't work, your aerators "may have" (or may not have) a flow restrictor in them. It's usually a metal disc with a small hole in the center. Try removing that flow restrictor and see if the water heater works better....

If not, before you go "pulling parts in desperation" contact your dealer. There may be a "silent recall" or a "technical service bulletin" that the service department has but is not available to the general public.....

[sourdough]

I don't use my fresh water tank and I've had aerators completely clogged with debris from who knows what during our first trips on some trailers.

[wifi_guy]

Originally Posted by JRTJH

Completely remove the faucet aerator and see if it works. If it does, then try cleaning the aerator because there is a significant amount of "construction debris" in the water tank/plumbing runs to block water flow through the aerator. This "fact of life with any RV" is the compelling reason to install a strainer on the inlet side of your water pump. Sucking up plastic drill shards from the fresh water tank is one of the primary reasons why water pumps fail.

If that doesn't work, your aerators "may have" (or may not have) a flow restrictor in them. It's usually a metal disc with a small hole in the center. Try removing that flow restrictor and see if the water heater works better....

If not, before you go "pulling parts in desperation" contact your dealer. There may be a "silent recall" or a "technical service bulletin" that the service department has but is not available to the general public.....

The issue is the low flow aerators installed in the faucets. After a lot of experimenting last night, I was able to physically hear what was going on this AM. My wife this AM was showering and fresh water pump was running the entire time, hence a constant flow water through the heater. While she was using the sink, the pump would run, ramp up pressure and shut off, run and ramp up and shut off. Physically hearing it helped me understand the issue more.

When we get home today I am going to verify that when hooked up to water the faucets and heat work as they should. If they do, maybe we just deal with this issue when using the water pump and fresh water tank. We don't camp a TON where we don't have full hook with water. So maybe we just deal with it.

I had the bathroom sink tore a part, I don't see how to not run these with the flow restrictors on. Without the aerators installed, water shoots everywhere. Not exactly ideal. LOL

If we hook this up to water and have the same issues at the sink faucets, I think I am faced with either A) swapping out the faucets or B) swapping out the low flow aerators. Can you buy different aerators for these faucets?

[wifi_guy]

Little update. So shower is 5Gallons per minute. Bathroom sinks are 1.5GPM. I found some new aerators on amazon that are 4.7GPM. Going to try them. Can't really hurt anything at this point. $4 fix if it works.

Not sure what I need in the kitchen sink yet.

[flybouy]

Just want to point out that in the original post you stated you were uesing the fresh water tank. If you often boondock then increasing the flow rate of the faucets will result in more water usage and filling the gray water tank quicker. A lot of faucets have aerators that have a flow restrictor that is just a thin disk with a small holenin the center. On that style you can remove that disc to try out your solution.

[wifi_guy]

Got back home yesterday. Hooked up to water. Set my pressure regulator to 40PSI. Kitchen and bathroom faucets worked no problem. So it's only an issue when using the water pump and fresh water.

I think we are going to leave well enough alone. We don't camp enough where we don't have full hookups for this to really be an issue worth diving into.

Thanks everyone for your help. Happy Camping!

[wifi_guy]

So what I ended up doing to fix this issue was I went and bought some new 4.5gpm aerators for the sinks. This fixed the issue and hot water now works when using the pump.

The original aerators you could barely blow air through them. They really restricted things.