FAQ
TL;DR: Close the coil return ≥50% and, "for gravity it is very important" to orient ports correctly; this curbs rapid DHW cooling on Galmet SGW(L)x2 double U‑coil setups. [Elektroda, W0jtek92, post #17263801]
Why it matters: Helps homeowners with gravity-fed systems fix lukewarm water after retrofits or upside‑down connections.
- Coil feed goes to the top connector; return at the bottom; "coil feed must be on the top coil connector." [Elektroda, W0jtek92, post #17265807]
- Throttle the coil return roughly halfway to curb thermosiphon and keep DHW hot longer. [Elektroda, W0jtek92, post #17293677]
- Reversing cold/hot DHW defeats the inlet anti‑mixing shutter, causing fast tank cooling during draws. [Elektroda, Wawrzyniec, post #17263655]
- Upside‑down mounting is incorrect; reinstall upright and set the valves as above. [Elektroda, W0jtek92, post #17265807]
- Reported outcome: a 120 L SGW(L)x2 gave two hot showers; the third was lukewarm before corrections. [Elektroda, pawelek00708, post #17278029]
Quick Facts
- Coil feed goes to the top connector; return at the bottom; "coil feed must be on the top coil connector." [Elektroda, W0jtek92, post #17265807]
- Throttle the coil return roughly halfway to curb thermosiphon and keep DHW hot longer. [Elektroda, W0jtek92, post #17293677]
- Reversing cold/hot DHW defeats the inlet anti‑mixing shutter, causing fast tank cooling during draws. [Elektroda, Wawrzyniec, post #17263655]
- Upside‑down mounting is incorrect; reinstall upright and set the valves as above. [Elektroda, W0jtek92, post #17265807]
- Reported outcome: a 120 L SGW(L)x2 gave two hot showers; the third was lukewarm before corrections. [Elektroda, pawelek00708, post #17278029]
How do I stop my Galmet SGW(L)x2 from losing heat so fast on gravity?
Throttle the coil return valve more than halfway to slow natural circulation. Keep the supply and return correctly oriented for gravity. This preserves stratification and reduces mixing during draws. If the system is fully gravity, consider partial conversion or balancing. This change usually fixes rapid cooling complaints. [Elektroda, W0jtek92, post #17263801]
Which coil port is the supply on a double U‑coil Galmet?
Use the upper coil connector for the hot supply from the stove or boiler. Connect the return to the lower coil connector. Open the upper valve fully, and balance the return downstream. As the expert said, "coil feed must be on the top coil connector." [Elektroda, W0jtek92, post #17265807]
Why does reversing the DHW cold and hot connections cool the tank quickly?
Cold water normally enters through a diffuser that limits mixing inside the tank. If you swap the connections, that anti‑mixing feature sits at the top. Cold water then mixes from the bottom during every draw and chills the tank. "There is a shutter that reduces the mixing of hot and cold water." [Elektroda, Wawrzyniec, post #17263655]
Do I need to convert a 100% gravity installation for this tank?
Edge case: 100% gravity circuits can self‑circulate and strip heat from the coil. Throttle the return hard, or add measures that limit unwanted flow. As the installer noted, "If you have an installation with 100% gravity, you have to convert it." This advice helps retain stored heat between draws. [Elektroda, W0jtek92, post #17263801]
What valve positions should I use after correcting the connections?
Fully open the valve on the upper coil connector (100%). Set the lower return valve around halfway (≈50%) to limit thermosiphon. Verify hot supply flows into the upper coil, and the cooler water returns below. This preserves stratification and stabilizes outlet temperature during draws. [Elektroda, W0jtek92, post #17265807]
Could misconnecting the tank’s DHW cold and hot cause lukewarm water at taps?
Yes. If cold and hot are reversed, the cold inlet diffuser cannot do its job. Cold inflow will mix with hot water and reduce outlet temperature quickly. You will notice fast cooling during consecutive showers. Correct the inlet and outlet to restore stratification. [Elektroda, Wawrzyniec, post #17263655]
Is it acceptable to mount the cylinder upside down to reuse existing pipes?
No. An upside‑down cylinder misplaces key internals and ports. Reinstall it upright and route the hot supply to the top coil connector. Then balance the lower return as needed. Avoid trusting paint colors on nozzles during reconnection. Follow the marked functions instead. [Elektroda, W0jtek92, post #17265807]
My 120 L SGW(L)x2 gives only two hot showers; is that normal?
One user reported two hot showers and a lukewarm third on a 120 L tank. That suggests stratification loss during draws. Check the orientation and return throttling as in this FAQ. [Elektroda, pawelek00708, post #17278029]
How can I verify my coil feed is on the correct connector?
Confirm the stove or boiler supply connects to the upper coil connector, as required. If it does not, reconnect so the upper coil is the feed. Then set the lower return as advised for gravity systems. [Elektroda, W0jtek92, post #17265807]
Do color caps on the ports matter when connecting?
Ignore paint colors on the nozzles. Follow functional markings and connect the hot supply to the upper coil connector. As the expert noted, "do not be suggested with colors on the nozzles." [Elektroda, W0jtek92, post #17265807]
What’s a simple 3‑step way to connect the SGW(L)x2 correctly in a gravity setup?
- Mount the cylinder upright so its top ports are at the top.
- Connect the hot supply to the upper coil; connect the return to the lower coil.
- Open the upper valve fully; set the lower return about halfway to limit thermosiphon. [Elektroda, W0jtek92, post #17265807]
I fixed the coil piping, but the tank still cools fast during draws—why?
If DHW in/out are reversed, the anti‑mixing baffle sits wrong. Cold water then enters low and mixes the tank during draws. Correct the DHW connections to restore the diffuser’s effect and preserve stratification. [Elektroda, Wawrzyniec, post #17263655]
