diff -r 98df69885455 -r 1fed3ff9a64e src/EditProduct.cpp
--- a/src/EditProduct.cpp	Sun Jan 15 14:33:53 2023 +0100
+++ b/src/EditProduct.cpp	Mon Jan 16 16:55:41 2023 +0100
@@ -492,7 +492,10 @@
     ui->brew_preboileffShow->setValue(product->brew_preboil_efficiency);
     ui->brew_aboilphEdit->setValue(product->brew_aboil_ph);
     ui->brew_aboilsgEdit->setValue(product->brew_aboil_sg);
-    ui->brew_aboilvolEdit->setValue(product->brew_aboil_volume + product->eq_chiller_volume);
+    if (product->brew_aboil_volume > 0)
+	ui->brew_aboilvolEdit->setValue(product->brew_aboil_volume + product->eq_chiller_volume);
+    else
+	ui->brew_aboilvolEdit->setValue(0);
     ui->brew_aboilvolShow->setValue(product->batch_size * 1.04 + product->eq_chiller_volume);
     ui->brew_aboileffShow->setValue(product->brew_aboil_efficiency);
     ui->brew_whirlpool9Edit->setValue(product->brew_whirlpool9);
@@ -863,6 +866,7 @@
 #include "EditProductTab10.cpp"
 #include "EditProductTab11.cpp"
 #include "EditProductTab12.cpp"
+#include "EditProductTab13.cpp"
 #include "EditProductExport.cpp"