diff --git a/tests/unit/handlers/coolingSystem.handlers.test.js b/tests/unit/handlers/coolingSystem.handlers.test.js
index 3b88359..1691645 100644
--- a/tests/unit/handlers/coolingSystem.handlers.test.js
+++ b/tests/unit/handlers/coolingSystem.handlers.test.js
@@ -62,8 +62,8 @@ const createMockEquipment = () => ({
     { equipment: 'TC-7501', is_active: true, miner_side_out_temp: { value: 37.1, unit: '°C' }, tower_side_in_temp: { value: 29.2, unit: '°C' }, tower_side_out_temp: { value: 36.9, unit: '°C' }, tcv_position: { value: 55, unit: '%' } }
   ],
   cooling_towers: [
-    { equipment: 'TR-7501', is_running: true, fan_status: 'Running', fan_cv: { value: 60, unit: 'CV' }, level: { value: 82, unit: '%' }, vibration: { value: 0.8, unit: 'mm/s', status: 'Normal' } },
-    { equipment: 'TR-7502', is_running: true, fan_status: 'Running', fan_cv: { value: 45, unit: 'CV' }, level: { value: 85, unit: '%' }, vibration: { value: 0.6, unit: 'mm/s', status: 'Normal' } }
+    { equipment: 'TR-7501', circuit: 'COOLING_TOWER', is_running: true, fan_status: 'Running', fan_cv: { value: 60, unit: 'CV' }, level: { value: 82, unit: '%' }, vibration: { value: 0.8, unit: 'mm/s', status: 'Normal' } },
+    { equipment: 'TR-7502', circuit: 'HVAC_CONDENSER', is_running: true, fan_status: 'Running', fan_cv: { value: 45, unit: 'CV' }, level: { value: 85, unit: '%' }, vibration: { value: 0.6, unit: 'mm/s', status: 'Normal' } }
   ],
   valves: [
     { equipment: 'PCV-7502', position: { value: 12, unit: '%' } },
@@ -1409,6 +1409,30 @@ test('6 - differential_pressure populated when per-group PTs configured', (t) =>
   t.pass()
 })
 
+test('6 - differential_pressure from single-transmitter array (supply/return/diff)', (t) => {
+  const equipment = createMockEquipment()
+  equipment.pressures = [
+    ...equipment.pressures,
+    { equipment: 'PT-7502-A', value: 2.81, unit: 'bar', supply_pressure: 2.81, return_pressure: 2.2, differential_pressure: 0.61 },
+    { equipment: 'PT-7502-B', value: 2.9, unit: 'bar', supply_pressure: 2.9, return_pressure: 2.3 }
+  ]
+  const config = createMockConfig()
+  config.cooling_system.miner_loop.line1.group_pressure_sensors = ['PT-7502-A', 'PT-7502-B']
+  const view = buildMinersCircuit1View(equipment, config)
+
+  const dp = view.lines[0].differential_pressure
+  t.is(dp.length, 2, 'one row per transmitter')
+  // Group 1: device-provided differential is preferred
+  t.is(dp[0].supply.tag, 'PT-7502-A', 'supply tag = transmitter id')
+  t.is(dp[0].return.tag, 'PT-7502-A', 'return tag = same transmitter id')
+  t.is(dp[0].supply.reading.value, 2.81, 'supply from supply_pressure')
+  t.is(dp[0].return.reading.value, 2.2, 'return from return_pressure')
+  t.is(dp[0].delta_p.value, 0.61, 'uses device-provided differential_pressure')
+  // Group 2: no device differential -> derived from supply - return
+  t.is(dp[1].delta_p.value, 0.6, 'derived delta-p = supply - return when DP absent')
+  t.pass()
+})
+
 test('7 - rack_statuses derived from live rack power (online = power > 0)', (t) => {
   const equipment = createMockEquipment()
   const config = createMockConfig()
diff --git a/workers/lib/server/handlers/cooling.system.handlers.js b/workers/lib/server/handlers/cooling.system.handlers.js
index fc0d328..3d49722 100644
--- a/workers/lib/server/handlers/cooling.system.handlers.js
+++ b/workers/lib/server/handlers/cooling.system.handlers.js
@@ -76,6 +76,34 @@ function buildVibrationSwitch (vibrationSwitches, switchTag) {
 
 function buildGroupDifferentialPressure (lineConfig, pressures) {
   const groupSensors = lineConfig.group_pressure_sensors || {}
+
+  if (Array.isArray(groupSensors)) {
+    return groupSensors.map((sensorId, i) => {
+      const pt = pressures?.find(s => s.equipment === sensorId) || null
+      const mkSlot = (val) => ({
+        tag: sensorId,
+        type: pt?.type || null,
+        reading: val != null ? { value: val, unit: pt?.unit || 'bar' } : null
+      })
+      const supply = mkSlot(pt?.supply_pressure)
+      const ret = mkSlot(pt?.return_pressure)
+      const supplyVal = supply.reading?.value
+      const returnVal = ret.reading?.value
+      const deltaPVal = pt?.differential_pressure != null
+        ? Math.round(pt.differential_pressure * 100) / 100
+        : (supplyVal != null && returnVal != null
+            ? Math.round((supplyVal - returnVal) * 100) / 100
+            : null)
+      const unit = supply.reading?.unit || ret.reading?.unit || pt?.unit || 'bar'
+      return {
+        group: i + 1,
+        supply,
+        return: ret,
+        delta_p: deltaPVal != null ? { value: deltaPVal, unit } : null
+      }
+    })
+  }
+
   const supplyIds = groupSensors.supply || []
   const returnIds = groupSensors.return || []
   const count = Math.max(supplyIds.length, returnIds.length)
@@ -183,13 +211,25 @@ function buildMinersCircuit1View (equipment, config) {
   // Compute summary values from line sensor data — units derived from sensors
   const tempUnit = lines[0]?.supply?.temperature?.unit
   const flowUnit = lines[0]?.supply?.flow?.unit
-  const pressureUnit = lines[0]?.supply?.pressure?.unit
+  // avg over the 16 per-group PTs, not the unset per-line pressure sensors
+  const allGroups = lines.flatMap(l => l.differential_pressure || [])
+  const pressureUnit = allGroups.find(g => g.supply?.reading?.unit)?.supply?.reading?.unit ||
+    allGroups.find(g => g.return?.reading?.unit)?.return?.reading?.unit ||
+    lines[0]?.supply?.pressure?.unit
 
   const allSupplyTemps = lines.map(l => l.supply.temperature?.value).filter(v => v != null)
   const allReturnTemps = lines.map(l => l.return.temperature?.value).filter(v => v != null)
   const allSupplyFlows = lines.map(l => l.supply.flow?.value).filter(v => v != null)
-  const allSupplyPressures = lines.map(l => l.supply.pressure?.value).filter(v => v != null)
-  const allReturnPressures = lines.map(l => l.return.pressure?.value).filter(v => v != null)
+  const groupSupplyPressures = allGroups.map(g => g.supply?.reading?.value).filter(v => v != null)
+  const groupReturnPressures = allGroups.map(g => g.return?.reading?.value).filter(v => v != null)
+  const allGroupDeltaP = allGroups.map(g => g.delta_p?.value).filter(v => v != null)
+  // prefer per-group PTs; fall back to line-level pressure
+  const allSupplyPressures = groupSupplyPressures.length > 0
+    ? groupSupplyPressures
+    : lines.map(l => l.supply.pressure?.value).filter(v => v != null)
+  const allReturnPressures = groupReturnPressures.length > 0
+    ? groupReturnPressures
+    : lines.map(l => l.return.pressure?.value).filter(v => v != null)
 
   const avgSupplyTemp = allSupplyTemps.length > 0
     ? Math.round((allSupplyTemps.reduce((a, b) => a + b, 0) / allSupplyTemps.length) * 10) / 10
@@ -213,9 +253,11 @@ function buildMinersCircuit1View (equipment, config) {
   const outletPressureAvg = allReturnPressures.length > 0
     ? Math.round((allReturnPressures.reduce((a, b) => a + b, 0) / allReturnPressures.length) * 100) / 100
     : null
-  const deltaPAvg = (inletPressureAvg != null && outletPressureAvg != null)
-    ? Math.round((inletPressureAvg - outletPressureAvg) * 100) / 100
-    : null
+  const deltaPAvg = allGroupDeltaP.length > 0
+    ? Math.round((allGroupDeltaP.reduce((a, b) => a + b, 0) / allGroupDeltaP.length) * 100) / 100
+    : ((inletPressureAvg != null && outletPressureAvg != null)
+        ? Math.round((inletPressureAvg - outletPressureAvg) * 100) / 100
+        : null)
 
   const controlValveEntries = coolingConfig.control_valves || {}
   const controlValves = {}
@@ -261,7 +303,7 @@ function buildMinersCircuit2View (equipment, config) {
   const temperatures = equipment.temperatures
   const levels = equipment.levels
   const heatExchangers = equipment.heat_exchangers
-  const coolingTowers = equipment.cooling_towers
+  const coolingTowers = (equipment.cooling_towers || []).filter(ct => ct.circuit === 'COOLING_TOWER')
   const vibrationSwitches = equipment.vibration_switches
   const valves = equipment.valves
   const tanks = equipment.tanks
@@ -321,19 +363,24 @@ function buildMinersCircuit2View (equipment, config) {
     }
   })
 
-  // Summary: pre-HX and post-HX temps from heat exchangers
+  // pre/post-HX from the loop's configured sensors, else HX-derived
+  const preHxConfigReading = getSensorReading(temperatures, towerConfig.pre_hx_temp_sensor)
+  const postHxConfigReading = getSensorReading(temperatures, towerConfig.post_hx_temp_sensor)
+
   const allTowerSideIn = heatExchangerData.map(hx => hx.tower_side_in_temp?.value).filter(v => v != null)
   const allTowerSideOut = heatExchangerData.map(hx => hx.tower_side_out_temp?.value).filter(v => v != null)
-  const preHxTemp = allTowerSideIn.length > 0
+  const hxPreHxTemp = allTowerSideIn.length > 0
     ? Math.round((allTowerSideIn.reduce((a, b) => a + b, 0) / allTowerSideIn.length) * 10) / 10
     : null
-  const postHxTemp = allTowerSideOut.length > 0
+  const hxPostHxTemp = allTowerSideOut.length > 0
     ? Math.round((allTowerSideOut.reduce((a, b) => a + b, 0) / allTowerSideOut.length) * 10) / 10
     : null
+  const preHxTemp = preHxConfigReading?.value ?? hxPreHxTemp
+  const postHxTemp = postHxConfigReading?.value ?? hxPostHxTemp
   const deltaT = (preHxTemp != null && postHxTemp != null)
     ? Math.round((postHxTemp - preHxTemp) * 10) / 10
     : null
-  const tempUnit = heatExchangerData[0]?.tower_side_in_temp?.unit
+  const tempUnit = preHxConfigReading?.unit || postHxConfigReading?.unit || heatExchangerData[0]?.tower_side_in_temp?.unit
 
   // Tower level from config sensor
   const towerLevelSensor = towerConfig.tower_level_sensor
@@ -706,7 +753,7 @@ function buildHvacCircuit2View (equipment, config) {
   const temperatures = equipment.temperatures
   const flows = equipment.flows
   const levels = equipment.levels
-  const coolingTowers = equipment.cooling_towers
+  const coolingTowers = (equipment.cooling_towers || []).filter(ct => ct.circuit === 'HVAC_CONDENSER')
   const condenserConfig = config?.cooling_system?.hvac_condenser || {}
   const viewConfig = config?.cooling_system?.view_metadata?.hvac?.circuit2 || {}