heating system simply wont keep up

Timco

Purge on return. Being pex, drain it and install shut-off valves on supply & return. Ball valves will work...you can get them in pex barb style to make for easy install. You paid for this, have it done right, safe and work!! Get rid of check valve and install a proper back flow preventer. Install a 30# relief valve. These are NOT bells & whistles...they are the basics a PRO would have installed. While the system is drained, change return to bottom, remove dip tube, and put in a temp & pressure gauge. They are available at almost any plumbing supply and are CHEAP!!

Tim

GW

idea

can you measure the amps on the element and confirm 4500 watts? You're sure there is no ground water issues? Yes, a picture would help, you're this far into it a 100 bucks on a digital won't be too painful now!

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Jim Hall

stupid question

Are there actual purge valves for sale or is this just a boiler drain valve and ball valve you use to get the air out of system. Is it advisable to use existing water heater drain cock to hookup return water too or should you actually drain tank and remove plastic drain and install a copper tube. I was thinking if I could use drain then I wouldn't have to drain water heater.

Bill Clinton_5

electric water heater

Probably I missed it somewhere in this long discussion, but I can't find anything that tells me the water heater is working. You may have it wired for 240v, but that doesn't mean you have a complete circuit.

Easy ways to test:

`1. turn off the pump and wait a few hours. then feel the pipes on the water heater. If they're cold, the sucker isn't working.

2. have someone stand at the meter and watch the little wheel go round and round while someone else turns the circuit on and off (if breaker is next to meter, one person can do both jobs) Does speed of wheel change?

If water heater is actuallly working, then you have no circulation. The photo shows piping that should be near impossible to purge, so you need to correct that even if you get system working.

The fact that the thermometers show slightly different temperatures does not mean there is flow: There is some heat from the pump and those thermometers are not that accurate anyhow.
If water heater is working and you have circulation, you're imagining things: That basement is warm.

Bill

Steve_35

Not so stupid questions.

There are purge valves available or you can use a ball valve and boiler drain.

I have a WH heating my shop. My return goes into the cold inlet. Coldest days of the year (-10F) my supply water needs to be about 120 to keep the shop at the setpoint of 63.

If you want to come in the bottom you can. They're usually 3/4"NPT.

Have you stuck an ammeter on your WH? I cannot believe it's running at full output and only delivering 95F water with a 5F deltaT.

According to my calcs if your water heater is working at 100% capacity and your temp rise is 5F you need to be moving about 6.3gpm through the system. If you spread that evenly through the 4 loops that's a little under 1.6gpm per loop. 1.6gpm across 2250' of 1/2" PEX is a little over 20' head. A Grundfos 15-58FC with the check valve removed won't move ANY water at that head. The number just don't work. Unless the water heater isn't putting out 15,400btuh which it will if it's wired properly and it's running all of the time.

You have other issues as well but your water heater isn't working right. My gut reaction is the elements are only getting 120v. Check the voltage at the elements. If it's 240v check the amperage.

Jim Hall

I have checked water heater and both elements are getting 240 volts when t-stat calls for them to. Also 4400 watts drawn on system(I am an electrician) I changed upper t-stat on water heater to 95 degrees and upped bottom to 120 degrees. I did get some more air out of system but will install ball valves and boiler valves this week. Also, will pipe return into bottom of water heater if this doesn't fix problem. I am trying to avoid draining water heater since I didn't install drain in floor near water heater and I will loose 10 gallons of glycol but at this point I am willing to do whatever it takes. If I repipe to bottom water heater I'm not sure of what is being said about circ pump do I need a larger one, smaller one, or will it start working once air is out of lines?

Jim Hall

I guess I should have stated that I am an electrician. I have checked voltage,current draw, continuity of elements, etc. I shut off circ pump for 2 hours today water temp coming into supply was 120 degrees for about 1/2 hour till dropped and equalized at around 90 degrees. I put a pressure tester on drain and originally got 45 psi, I drained a little water to drop pressure to 15 psi, got some more air to come out of micro bubbler but will install ball valves and boiler valves on return loops this week and purge each zone individually to get rid of extra air. If that doesn't work I will re pipe return to bottom of water heater. If that doesn't work I will probably shoot myself. Ha Ha.

Jim Hall

1000' of 1/2" pex in well insulated slab 10' below grade. slab is 1200 sq ft.

Jim Hall

check valve is still installed in pump. Would I be better off having 2 pumps running 2 loops each?

Steve_35

Try changing the top element to 120.

Timco

One circ (especially your 15-58) will run this fine...you need balance with a real pex manifold or with ball valves. I would be more concerned about no BFP or 30# relief. Then re-pipe and balance once you can purge and know what your pressure / temp is. Have your plumber read this ENTIRE thread. You BOTH should learn something...about the system & safty....Next!

Tim

Jim Hall

thanks for all your help. Will be at parts counter in morning and install needed parts later in week. Will keep you guys posted as to progress. Thanks again.

Timco

Hope it works out...I too was a sparky. That is my dog's name as well. I roped custom mansions for a few years before running 750MCM and designing large services for large commercial buildings. I loved setting the big cans & pulling the big wire!

Tim

Weezbo

i feel your struggle...

here are a few suggestions purchase some full port ball valves ,for the supply and return to the Fluid heater.

get 8, 3/4 pex 1/4 turn ball valves,for the individual supply and return lines.

12 3/4 pex t's 8 of these you can install beneath the ball valves , the other 4 you can use for temp gauges above the ball valves on the returns...somewhat near the header maybe 4' away or so from the existing pex fitting to copper coupling.

10 threaded no kink boiler drain valves 8 3/4pex to 3/4 cu threaded fm adaptors. two mor for some 2 1X3/4 copper 'T's to tap into the headers.

a sweat ball valve on the system side of the check would work for though a backflow preventor and prv might be a real good thing at this time also.now

bolt it all together into your lash up.... bust out your water heater hoses and transfer pump or buy one more no kink sweat valve and T and burn that it in ahead of the backflow preventor and the boiler pressure reducing valve...that way you can use it as a fast fill with full available water pressure to purge the lines one at a time. get a bucket and pump water one direction supply to return on each of the gated lines and into the bucket and keep the hose under the fluid so wou can see the air bubbles...if nothing comes out of the suspect line...then open the other pipe of the same colour with the hose now installed into the bucket to the no kink on that line...

if you get flow one is the supply and one is the return..no flow? increase the pressure with a compressor on both of the pipes you have tested (like 100 psi air) with water in it... one of them has to have circulation.if not maybe it is frozen or seriously kinked...if it is kinked then you may have to push some hydraulic brake line hose down the pipe until it gets where it hits something.... if you cannot get it to thaw out its kinked and you will have to find it and fix it if you want it to GO.


just how well it will heat is anyones guess however you may be able to zazz up the net ball court first then the rest of the slab .....if it works then you may have to use different temps to the areas and or Zone the system.... it is late so i going to get some rest...*~/:)

if you want to think the wiring and zoning controls you found a pool of talent ...honestly you could get hundreds of answers to whats what with it if you do this then what if you do that then what?

hook into what you "see".

flow with it

i will say this too, there are many ways to pipe something like this from the get go that do not resemble what you have spent your time doing...if you did not pipe it in then your friend has his own method of doing things maybe he has a few ideas of his own....might want to get him to give you some help....however in his exhubrance to save dollars on the install hes made maint of the system expensive.... got to ba;ance those sort of things early...

Unknown

There is no such thing as too much flow from a heat transfer standpoint. The water can't go "too fast" to give up heat. The average temperature of the circuit would be higher and it would technically give up MORE heat because of that.

This problem is not related to a pump pushing too fast.

Unknown

turn it back on. if the bubbler is removing air, and you don't have makeup, system pressure drops.. flow problems result.

GW

math

It seems as though (based on the pic and the comments) you need some serious purging action!

Anyways, one guy mentioned "you can't have too much flow"... what is wrong with the message board? I saw it in my email but it's not here...

I agree, more flow might mean less delta T, yet math says that gpm x dT x 500 is BTU. So if flow goes up, dT goes down, yet it's the same a low flow and high dT from a stanpoint of math.

Also, same goes with electricty, correct me if I'm wrong, but i beleive that 120v will still produce 4500 watts, only the amps will double. I'm not an electrician, just know some basics.

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Steve_35

Math 2

NRT Bob mentioned that. I think it's showing up as the first posting that has his name. The messages aren't posted in date order but rather in reply order. So his reply was to an older message than the one you replied to.

The thing that befuddles me is how the water heater can produce more btuh than is being delivered yet the water temp doesn't increase. Tells me the WH isn't running all of the time despite assurances to the contrary. The heat HAS to go somewhere.

The electric formula here is V=I*R with
V = Volts
I = Impedance (Amps)
R = Resistance (Ohms)

The resistance doesn't change here so if the voltage drops the amps have to follow. So if the voltage is cut in half so is the amperage and the watts are 1/4.

GW

ahh

I see the post now.

There's ground water, or the slab is kicking the 15,000 BTU's in the pants.

try running just ONE CIRCUIT at a time. Try one, let it heat up. Shut it off, let the next heat up, come up to temp. So on. Then try two at a time. and so on. there has to be a magic potion here somewhere.

You're so right, the energy is going somewhere, and it appears from this standpoint the lines are indeed purged.

Do the one at a time method please.

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Steve_35

If the slab was kicking butt

the deltaT would be greater. And at 15,000btuh with a 5F deltaT means there's got to be a 6+gpm flow. No way are you going to get 1.5+gpm through 250' of 1/2" PEX with a Grundfos 15-58.

That's why I say the WH isn't on 24/7. Not if it's got 240V to the elements.

Be interesting to see exactly what the resolution is. He has the top t-stat set at 95 and the bottom at 120. What do you think of that, Gary? And the supply water is 95. Coincidence?

GW

min

> the deltaT would be greater. And at 15,000btuh

> with a 5F deltaT means there's got to be a 6+gpm

> flow. No way are you going to get 1.5+gpm

> through 250' of 1/2" PEX with a Grundfos

> 15-58.

>

> That's why I say the WH isn't on 24/7.

> Not if it's got 240V to the elements.

>

> Be

> interesting to see exactly what the resolution

> is. He has the top t-stat set at 95 and the

> bottom at 120. What do you think of that, Gary?

> And the supply water is 95. Coincidence?





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GW

you're right

I'm sitting around past my bedtime doodling on MS Paint (drawing a big job we're doing) and digging some iTunes.

So the upper stat is 95? How do we all miss that? I'm glad someone is paying attention!

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AJF

heating unit

My furnance just continues to blow. When the temp drops it blows heat.
when the heat stops it keeps blowing. The fan does not appear to come on.

Steve_35

You may get more help if you start a new thread.

And you need to have a little better description. You say it keeps blowing and the fan doesn't appear to come on? Please remember most furnaces have more than one fan or blower.

Jim Hall

return is piped into top of water heater so I thought if I turned bottom stat up higher than top stat that top thermostat wouldn't just short cycle on and off at least the bottom stat would stay on more and heat the water. Don't know if it has helped much. I shut off loop 1 so I am only running loops 2 and 4 (loop 3 is dead) and water coming in is at 110 and returning at 95. I am thinking of draining tank re routing return to bottom of tank and replacing 4500 watt elements with 5500 watt elements. Any ideas on this?

Keith Johnston_2

Glycol?

DId you mention that there was Glycol in the system? From what I have learned here that will affect the flow rate and may allow the pros to help with your problem.