Question about Pool & Spa

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I have an Astral HX120 Spa heater without any markings to state which is the inlet / outlet water connections. I'm assuming looking at the back of the unit, the left is the inlet. Is this correct?

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Paul G

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If it’s the pump your talking about, the centre is the inlet and the top is the outlet.

Posted on Nov 14, 2019


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robert samples

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SOURCE: Connecting the hot water line to a new dishwasher.

use teflon tape on the elbow if you did the back it off put some more on it and stop when its snugged facing the right direction now ive torqued them things pretty tight my self they don't strip that easy

Posted on Feb 16, 2008



  • 125 Answers

SOURCE: Spa water drains to pool

Here is a link to the Aqualink website so you can download a trouble shooting guide.

Posted on Feb 26, 2009

Eric Schultz

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SOURCE: Carver cascade 2 No water at all comes out of the

Check the tank drain valve for water there.If you get a good water flow there you know the tank is getting water pressure.Check the first outlet downline from WH and if there is no water there you have a blockage or other problem.If you have to turn off water to tank, remove the outlet pipe ,and check for water flow from tank with in valve on.If no flow, tank is plugged up.
Hope this gets you going.

Posted on Oct 06, 2009

Testimonial: "Confirmed my diagnosis. Any idea how to get it unblocked?"


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SOURCE: lay z spa water pump is faulty where can I get a

Hi Im Chris From BVL Elecric,
I cover Bournemouth and surrounding areas and supply solutions to most home electrical problems.
A lovely lady customer called me out today to diagnose faulty
pump/heater that kept tripping the RCD.
After scouring the net and finding this same problem over and over again but no solution,I decided to get personal with the blighter!!!
RESULT:- problem solved,
Customer very happy,
no new parts fitted,
water heating fine now.
If you live in my coverage area,have a LAY-Z-SPA that is faulty,no or limited warranty then give me a ring and I will be only to happy to come on over and fix it for a small fee.
just think that dead spa/pool heater/pump could be heating your water again tomorrow and there is plenty of summer left to enjoy it.
You can find my details quite easily , just google BVL Electric Bournemouth

Posted on Jul 02, 2010

Ryan Ross

  • 19 Answers

SOURCE: pool and spa heater will not turn on, low pressure on display

1) check the fuse on the transformer. You will get "low pressure" if the fuse is blown.
1a) remove front panel with flat head screw driver turning both big screws 1/4 turn clockwise
1b) look up under the 1 remaining front piece for 2 screws (one on each side). remove them and the 1 small panel slides down
1c) transform is directly in the center of this compartment
1d) red wire on transform has a black fuse case - twist open and check fuse (with an ohm meter it should read a dead short if it is working).
1e) if not working - replace with standard 250v 2a bus fuse.
2) it really is low pressure
2a) backwash pool or at least make sure pressure in filter take is not too high (high filter tank pressure == low water pressure in heater)
2b) if you have a bypass valve make sure it is not in bypass mode so most all pressure from the pump is going tothe heater
2c) right next to the transformer is the pressure switch. It has a small copper tube attached to the back and 2 wires in the front. Put an ohm meter across the two leads on this device. With the filter off it should be open, with the filter on it should be closed (short). If not either the copper tubing is clogged, the switch is faulty, or there is not enough water going through the heater. The amount of water that goes into the heater is adjustable and the water pressure switch is also adjustable. The owners manual explains how to adjust both but neither should need adjustment unless you have a special configuration (explained in the manual).

Posted on Sep 20, 2010

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1 Answer

Where is the temp sensor on a Hayward H300 ED2 pool heater

Hayward H series with ED option have electronic ignition with one or two dial thermostats. Along with thermostats, there are other temperature safety switches to shutdown the heater in case of over temperature, both for water temperature and for interior cabinet temperature.

CAUTION: Always turn off power, gas and the water pump whenever repairing your Hayward H series pool heater.

CAUTION: The Hayward H series pool heater is essentially a gas furnace. Only a qualified technician with proper training and tools should make repairs of your heater.

I'm assuming you are seeking the location for the thermostat sensor rather than the temperature switches, and I'm assuming you have dial-style thermostat(s). Incoming water temperature is measured at the inlet of the water heat exchanger. For most H series models, provision is made for two thermowells. If your unit has dual thermostats, both of these wells will have a bulb-style sensor inserted directly into the thermowells. If only one thermostat, then one of the thermowell ports will be sealed with a plug. The factory orientation of the water inlet and outlet is on the right side of the heater (as you face the front), but the installer has the option to locate the inlet/outlet on the left side with a field modification. Check your particular inlet/outlet orientation for either right or left side.

The heat exchanger thermowells and the thermostat sensors are located directly behind a two metal access plates that surrounds the heat exchanger inlet and outlet ports. Several Phillips-style screws secure the access plates to the heater cabinet. After several years of outside operation, these screws will likely be corroded and need some anti-rust oil to aid in their removal. When you have completed your examination of the thermowells and thermostat bulbs, I recommend applying some grease to the screws before re-assembly.

Once the access plates have been removed, the thermo-wells can be seen on the left side of the heat exchanger, which is the inlet side. Use the arrows on the top of the heat exchanger as a guide for inlet an outlet. The thermostat sensor bulb is directly inserted into the thermowell without any securing mechanism other than a copper or brass friction strip. I have seen some situations where a small amount of fiberglass has been inserted behind the bulb. The bulb should be inserted all the way into the thermowell until it touches the back. The copper or brass strip is used to keep the bulb in contact with the sides of the thermowell.

(For non-dial thermostat systems, the inlet water temperature measurement is made in the same location, but with a different device.)

CAUTION: The thermostat sensor is a liquid-filled thermo-expansion sensor. It relies on the thermo-expansion properties of a non-compressible fluid to operate the thermostat switch. Take care to not crush or kink the capillary tube between the sensor bulb and the dial thermostat switch.

If you remove the sensor bulb, take care to capture the copper/brass strip in order to use during re-insertion.

NOTE: Thermowells are sized to the particular thermostat sensor bulb. If you replace the thermostat sensor be sure to use the same size sensor bulb as the one being removed. If this is not possible, the thermowell may also need to be replaced.

Check your manual for verification of part numbers. The H series dial thermostat part number is CHXTSW1931. The matching thermowell is CHXTBW1930.

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1 Answer

Were is cold water inlet and hot water outel on model 71-40d b

Cold inlet and hot outlet are marked on top of water heater.
Usually there is a letter or word embossed into the metal top.

If tank is connected, then turn on hot water tap for a few moment and feel which pipe is hot.

Cold water enters bottom of tank through dip tube located on cold side. If hot and cold are reversed, the water heater will not perform as expected.

If you need further help, I’m available over the phone at

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My waterheater has three water connections on the top of it one has a C for cold is that a inlet or outlet ? The other spot has a H for hot is that a inlet or outlet ? And the other one is not marked what...

My water heater has three water connections on the top of it one has a C for cold is that a inlet or outlet ? IT'S THE COLD INLET. The other spot has a H for hot is that a inlet or outlet ? IT'S THE HOT OUTLET. And the other one is not marked what is that one for and is it a inlet or outlet ? please email me at [email protected] The last one is a pressure release valve that lets off excessive pressure when the temperature goes too high in the unit. When you install the heater, it should be installed into the drain pan that existed before or into a new one. You should also install a drain pipe from the valve to that drain pan, or into the drainage system for the house. This may depend on the codes where you live. Also install a good quality shut off valve on the inlet side for emergencies. A Ball type is good. Hope this helps,
Best Mark
I'm new to this site, so I'm not sure if I can email you directly or not. I believe not. Good Luck.

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Where is heater control valve on 2003 dodge ram pick up

THERE IS NO HEATER CONTROL VALVE ON THE WATER HOSES. NEW HEATER CORE. INLET LINE right before heater core hot, outlet after core look warm. Burped cooling system 5 times with engine at operating temp. Installed homade burp VALVE right after heater core outlet(high part of hose). Still no heat. Removed water pump, impeller still in good shape not stripped off shaft. Removed heater core hoses flushed water thrue the connections on the block to the water pump INLET and outlet. flushed water thrue heater core and hoses. Going to put it back togeter today. Used known good gauge to check water temp for operating temp in test. 195 f

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Raypak 2100 Heater wont fire unless the pressure switch is jumped. Replaced pressure switch and still same issue. Whats next?

Usually when these are plumbed in there is a bypass valve allowing you to run your filter and system withouth the heater. There would be a valve before and after the heater (which should be open) and a valve connecting the inlet and outlets ( this valve should be closed) Make sure you're not "bypassing: most of the water flow. If this isn't the problem then try the following: This switch is designed to prove flow. If you don't have enough flow to cause enough back pressure to make switch, then it assumes you dont' have flow. First make sure your filter is clean, and your skimmer and pump baskets are clean so you're pumping maximum volume of water. If these are clean have an assistant or two hold their hands on your discharge ports in the pool. If this backpressure cause the switch to close then you might try slightly smaller return jets to your pool. You can not the pressure on your filter and compare it to the pressure setting on the switch.

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1 Answer

I have a raypak heater when i fire it up the water temp go's up real fast

I assume this is on a swimming pool. It might depend on how it is plumbed in. Quite often, there is a bypass valve allowing the pool water to bypass the heater incase it's being serviced, or a leak etc. You would close inlet and outlet valves to heater and open the bypass. This would isolate the heater. If you have the bypass open while heating, you will reduce (or eliminate) the flow through the heater. This will allow the water in the heater to heat very fast, and lets be glad there's a temp control or your plumbing would melt. These heaters should have full flow through the heater, and you'll see min temp rise per pass.

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1 Answer

My Raypak versa gas heater for my hot tub will not heat the tub more then 96F, temp control is turned all the way up, just stated doing this, it was fine for a year, thanks

Water flo through the heater is too fast and the water can't get hot enough. Your by-pass valve is stuck closed and you need to open your water header and check it out. Or you may have an external by pass that need's to be opened 10-20%. This will be a valve between the inlet and outlet water pipes going to the heater. Good luck and HAPPY NEW YEAR.

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This heater has a thermal regulator and a high limit that could be the problems. If it were a high limit that was bad, the display would show the error when the heater goes off. In the absence of an error, one would look to the regulator. A bad regulator would cause the water flow to bypass the exchanger and cause a slow heat. The part is easily replaced and runs about $90. It sort of looks like a car thermostat and also has a spring. It is accessed by removing the large black plug near the plumbing inlet/outlet.

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