Hydronic system not moving antifreeze in garage

jjmik

It’s the lowest end Richmond. I think it is 3.9 gpm max ?

nicholas bonham-carter

The Richmond water heater line appears to have a number of problems, reported by users, and seems not to mention being used for hydronic space heating.
Maybe you will need a real boiler for this project.—NBC

Zman

You need to ask yourself, what changed?

The new hot water heater has much higher resistance than your old tank. If you can dig up those specs, it would help with the sizing.

No one, I mean no one, uses 100% glycol. Commercial snowmelt systems only use 50%.
100% glycol is a nightmare to pump. 30% is pretty much the norm unless you plan to turn off the heat in the winter.

As mentioned above, the expansion tank location will make air removal difficult. Your tubing looks like 1/2".

kcopp

Tankless is the wrong application here.
That being said...
Primary secondary is an absolute must.
Ditch the glycol...its adds too much head to the system as well as poor heat transfer. The system may moan when heating. Noritz prohibits it in their systems.
Furthermore those manifolds also are pretty restrictive... I have had issues w/ them adding a ton of head to the system and getting little or no flow.... Did you add them?

HomerJSmith

Hercules Cryo-tek 100 is a 50% solution of water and glyco at 100% on the chart. A 3 to 2 mixture is about 35% glyco. Glyco shouldn't be less than 25% in a system as lower concentrations can lead to bacteria contamination of the fluid. You can figure, off hand, that using glyco will lower the head energy of a pump by about 10% on the pump curve, depending on the concentration of glycol and sys operating temp. Use only the necessary concentration to keep the sys from reaching a non pumpable condition at the coldest temp you think you will experience.

Are you sure you don't have an air lock somewhere? Is the manifold air vents caps loose so that air can escape out of the mainfolds? You don't have air trapped in the piping higher than the manifolds, do you? In other words, you are sure that you got all the air out of the system. How did you fill the sys with the glycol mixture?

Are the flow indicators on the manifolds open and not in a closed position?

It would probably be better to use a multi-speed pump that you can switch between head energy outputs.

The required flow thru the Richman may be greater than the flow thru the manifolds and may require a buffer tank?

jjmik

today’s progress... or attempts.. I have replumbed the system and added a second pump. But did not do the primary secondary. Added a pump just before the inlet. And have one after the expansion tank. Refilled the lines and the water heater is running. The flow meters on the manifold are wide open. Although the needles are not showing any flow.

Question.. on the air valve above the expansion tank. Does that need to stay closed or open? If I open it to release the air. My pressure drops to zero. Is this what I want? Right now the inlet pressure is at 20 and the outlet pressure is at 10-12 I did mix more water into the system. I am going to use the test strips to test my mixture

Gordy

No the x tank needs to have 12 psi in your case. It needs to be checked isolated from the system.

jjmik

> @Gordy said:
> No the x tank needs to have 12 psi in your case. It needs to be checked isolated from the system.

The tank is set at 12 psi. If I open the air vent all my pressure drops and the heater shuts off. Is that supposed to stay closed? Everything I read says it stays open

jjmik

I just repressurized the system with the valve open and my pressure is now staying . But the heater did not stay on.

Gordy

That’s the air separator yes that vent stays open. It’s removing trapped air. If it’s large quantities being removed you will lose pressure, and have to top off the system. Proof that there is still air from improper purging to the system.

I thought you were speaking of the Valve on the expansion tank.

jjmik

> @Gordy said:
> That’s the air separator yes that vent stays open. It’s removing trapped air. If it’s large quantities being removed you will lose pressure, and have to top off the system. Proof that there is still air from improper purging to the system.
>
> I thought you were speaking of the Valve on the expansion tank.

Pressure is staying up now. But I realized what the coding is on the thermostat. It’s telling me there’s not enough flow to the heater.. so I am going to have to upgrade my pumps. It ran for a good 45 minutes until I opened the air vent. Now it’s giving me the no flow code.

Thank you for all your help!! I greatly appreciated it!! I will update once I can purchase new pumps

kcopp

Cant say it enough. Primary / secondary....
Purge w/ water then if you must add the glycol.

hot_rod

If you have two of the NRF22, do as Gordy suggested and put them in series, basically bolt on to the other. Two in series double the head. Arrows in the same direction

4 gpm at 24', about the same as the Grundfos 26-99, and you already have them. I think?

HomerJSmith

Air scoops are a poor air eliminator. They usually have an arrow on the side indicating the flow direction. Is yours mounted with the correct direction of flow?

Is the PEX that you used a non barrier PEX? If it is you are going to have oxygen migration into the water from the outside. A coalescence micro bubbler air elimination device would have been a better choice.

Make sure all the flows are in the right & same direction. The pumps don't have to be closed coupled. You could even have a push-pull configuration thru the Richmond. Are there any water valves or air vents in the Richmond that may be shut off?

This is a stupid question, but do you have power to the pumps and are they rotating.

Are you sure you got all the air out of the sys and how did you do it?
You need a pump that will have a flow of 2'/sec to move air out of the system. A Caleffi purge valve is ideal. 'hot rod' did a Caleffi Idronics video on this very subject. Purge only one manifold circuit at a time until the water runs bubble free.

https://www.youtube.com/watch?v=raHCtObGOhY

Gordy

If there is air in the piping, and it hits the circulator flow stops. So need to get that straightened out, or no pump will work. Circulators, and flow should be near silent. If you hear cavitation, or gurgling that’s air making its way around the system.

GBart

Viega Pro Radiant Design manual, something is wrong, boiler manual should have some piping examples.

https://www.viega.us/content/dam/viega/aem_online_assets/download_assets/us/impr_566442_0218_design_manual.pdf

jjmik

I ran coolant through all the lines for about 10 minutes. With a 150 gph drill pump . Including each single loop until I seen no air bubbles. Both pumps are set one on the inlet side and one one the outlet side after the X tank. At first it had just enough flow to run but once I bled the remaining air out and recharged the pressure it gives me a p1 code meaning not enough flow. I will go back and run the pump again to make sure all the air is out . And still need to check the glycol mix and dilute it more if needed.

GBart

page 46 of that manual gives an equation to figure out head requirement with different % of anti freeze

GroundUp

The reason your old WH was crapping out every year is because they are not designed for space heating; this tankless is not either. NRF-22 is plenty of pump for a floor of that size, but if I'm not mistaken, the orifice size in those tankless units is tiny and will restrict flow severely. Moving the existing pump to pull through the air separator and push into the return of the tankless would be making more of this situation, and I feel like you would be better off piping it primary secondary instead of trying to force what you have. Better yet, sell the tankless and buy a boiler designed for radiant heating. How can you be so sure you've got all the air out? I see no mention of how the loops were purged. You're going to want to dilute the glycol down to 30-40% as well, no less than 30. It'll never get cold enough to freeze even at 40%, so straight is only detrimental to your system. I run 45% in my snowmelt which sits stagnant in -30F weather all the time until it's needed, pumps hard at that temp but still flows. I think you're airlocked personally, but the combination of any air along with high concentration antifreeze and tiny orifice in the Richmond may be enough to kill it as well

jjmik

Can I use a Grundfos 26-99 with the nrf-22? The problem is.. I am out of work for the next few weeks and out of money. I’ve akready invested in over 1500$ on this setup. I can return one pump and purchase the Grundfos if that will do the trick. And thinning out the glycol. I’m kind of at a slump . So I’m going to have to make due with what I have. The guy that owned the house before me said he never had an issue with the water heater. I think my issue was the antifreeze was very old and needed to be replaced. It was car antifreeze and it was brown instead of green.

nicholas bonham-carter

In a few weeks, it will be warm. Why not return all the questionable items, and regroup/reinstall over the summer.
That water heater will never be satisfactory, even if you get the water to start flowing. It’s designed to heat a small flow of water to a higher temperature, instead of a lot of water a few degrees at a time.—NBC

jjmik

> @nicholas bonham-carter said:
> In a few weeks, it will be warm. Why not return all the questionable items, and regroup/reinstall over the summer.
> That water heater will never be satisfactory, even if you get the water to start flowing. It’s designed to heat a small flow of water to a higher temperature, instead of a lot of water a few degrees at a time.—NBC

Not doubting .. but why does the manufacture accept tankless heaters as hydronic systems now. Even gives you directions in the owners manual how to set up closed loop systems?

hot_rod

I don't see any info at the Richmond site as to pressure drop thru that heater, some manufacturers include that data. So sizing a circ pump will be somewhat of a guess. Past experiences here have indicated a high head version like the 26-99 may be adequate.

As NBC mentioned this unit is designed to do the exact opposite of what you need. It generates small amounts of hot water (flow) at a large temperature increase 55- 120 for DHW for example.

In a radiant application you may need higher flow and less temperature differential. Basically they are intended to heat small flows instantly.

Yes you can "force" them to work to a certain degree, it involves throwing more pumping power at it.

Upsize the circulator, dilute the glycol. An inexpensive floating ball type automotive antifreeze tester will help you zero in on the mix %.

jjmik

> @hot rod said:
> I don't see any info at the Richmond site as to pressure drop thru that heater, some manufacturers include that data. So sizing a circ pump will be somewhat of a guess. Past experiences here have indicated a high head version like the 26-99 may be adequate.
>
> As NBC mentioned this unit is designed to do the exact opposite of what you need. It generates small amounts of hot water (flow) at a large temperature increase 55- 120 for DHW for example.
>
> In a radiant application you may need higher flow and less temperature differential. Basically they are intended to heat small flows instantly.
>
> Yes you can "force" them to work to a certain degree, it involves throwing more pumping power at it.
>
> Upsize the circulator, dilute the glycol. An inexpensive floating ball type automotive antifreeze tester will help you zero in on the mix %.


Thank you! I plan on ordering the Grundfos . And taking my time to get this done right. It is warming up outside so I do t have to rush it

HomerJSmith

No, a automotive ball type anti-freeze tester is not for Cryo-tek 100. Go on Amazon, Ebay, or DHgate.com and buy a refractometer for less than $20 and use that to test your glycol concentrations.

The way a tankless water heater works is it turns on when there is a pressure drop on the hot water line. The Richmond may not be seeing a pressure drop, therefore not turning on. You may have to wire the pressure switch thru a relay to fool the Richmond into thinking that there is a pressure drop. Have I got that right?

Did we ever ascertain the model # of the Richmond? They make a large line of tankless heaters and I would like to look at the manual. Post a link to it.

jjmik, I stand corrected it is a turbine flow indicator most probably and not a pressure drop sensing mechanism.

jjmik

It is the Richmond essential plus gas tankless 6.4 gph. And I’m thinking it goes by flow. Not pressure drop. I’m getting a low flow error code. So that’s why I’m guessing that. Could be wrong tho

Gordy

As @hot rod pointed out, and I have researched, also Richmond does not give pressure drops for their heat exchangers nor a piping diagram for radiant applications.

With out knowing the hx pressure drop the calculations for pump size become a guess. As hot rod pointed out.

Purging with a 150 gph drill pump is not good enough to do purging forcefully. You need domestic water supply pressure to really be sure you get all the air out. With that drill pump you are probably not getting the 150 with out correct rpms of the drill, and you have restrictive components. Lucky if it’s pumping 1 gpm.

I understand your situation it’s to bad you didn’t find this website sooner. You are not the first.

First thing is power purge to be sure all air is out of system. With trapped air no pump will move the water.

Dilute anti freeze

Then lash the two nrf 22s in series after the expansion tank, not spread out bolt them together. With them spread out in between other restrictions you lose some head capability.

Gordy

jjmik said:

It is the Richmond essential plus gas tankless 6.4 gph. And I’m thinking it goes by flow. Not pressure drop. I’m getting a low flow error code. So that’s why I’m guessing that. Could be wrong tho

It doesn’t matter that the code sensor keys on gpm flow rate. Pressure drop is what needs to be known to correctly size a pump. So you get the proper flow.

Gordy

You are getting helpful information, but you gotta listen. Honestly I would ditch the tankless as been recommended. If you can’t return it that’s another matter. It surely won’t be as efficient as a boiler no matter what the efficiency rating is. It’s not being used in that application. It’s over sized btu wise for the load.

jjmik

I know and I understand you guys are give me great information but I am kind of stuck with this one as in I do not have $2000 to drop into a boiler system . Unfortunately I think I’m going to have to make do with what I have for right now hopefully this will last me another winter season or more once I get it up and running and then I can invest into an actual boiler .

hot_rod

HomerJSmith said:

No, a automotive ball type anti-freeze tester is not for Cryo-tek 100. Go on Amazon, Ebay, or DHgate.com and buy a refractometer for less than $20 and use that to test your glycol concentrations.

The way a tankless water heater works is it turns on when there is a pressure drop on the hot water line. The Richmond may not be seeing a pressure drop, therefore not turning on. You may have to wire the pressure switch thru a relay to fool the Richmond into thinking that there is a pressure drop. Have I got that right?

Did we ever ascertain the model # of the Richmond? They make a large line of tankless heaters and I would like to look at the manual. Post a link to it.

IF you buy a PG specific tester it will read PG hydronic fluid accurately. As accurate as they are.

A refractometer is prefer buy much more $$. My meter reads PG on one side of the scale, EG on the other.

jjmik

I purchased the test strips designed for the cryotech . Haven’t used them yet .

HomerJSmith

I quickly read all the posts to see if anyone mentioned the inlet water filter.

Is it possible that the inlet water filter is clogged and that's why there is insufficient flow? I believe it is the black knob on the right side inlet above the union.

Shut off the inlet and outlet ball valves an take it out and check it. Hold a pan under it as the water will come out of the heat exchanger.

jjmik

> @HomerJSmith said:
> I quickly read all the posts to see if anyone mentioned the inlet water filter.
>
> Is it possible that the inlet water filter is clogged and that's why there is insufficient flow? I believe it is the black knob on the right side inlet above the union.
>
> Shut off the inlet and outlet ball valves an take it out and check it. Hold a pan under it as the water will come out of the heat exchanger.

I have checked both Y filter and heater filter several times. Because there is some old film left in the piping from the previous fluids . I flushed out the system for over an hour with a garden hose. But there’s still some stuff in the pex piping