diff --git a/services/web/app/src/Features/Compile/ClsiManager.js b/services/web/app/src/Features/Compile/ClsiManager.js
index 3c09b003ae..fb06b19c0a 100644
--- a/services/web/app/src/Features/Compile/ClsiManager.js
+++ b/services/web/app/src/Features/Compile/ClsiManager.js
@@ -45,6 +45,13 @@ const ClsiManager = {
             { ...options, syncType: 'full' },
             callback
           )
+        } else if (status === 'unavailable') {
+          return ClsiManager.sendRequestOnce(
+            projectId,
+            userId,
+            { ...options, syncType: 'full', forceNewClsiServer: true },
+            callback
+          )
         }
         callback(null, status, ...result)
       }
@@ -173,6 +180,22 @@ const ClsiManager = {
     if (options == null) {
       options = {}
     }
+    if (options.forceNewClsiServer) {
+      // Clear clsi cookie, then try again
+      return ClsiCookieManager.clearServerId(projectId, err => {
+        if (err) {
+          return callback(err)
+        }
+        options.forceNewClsiServer = false // backend has now been reset
+        return ClsiManager._sendBuiltRequest(
+          projectId,
+          userId,
+          req,
+          options,
+          callback
+        )
+      })
+    }
     ClsiFormatChecker.checkRecoursesForProblems(
       req.compile != null ? req.compile.resources : undefined,
       (err, validationProblems) => {
@@ -434,6 +457,8 @@ const ClsiManager = {
         callback(null, { compile: { status: 'conflict' } })
       } else if (response.statusCode === 423) {
         callback(null, { compile: { status: 'compile-in-progress' } })
+      } else if (response.statusCode === 503) {
+        callback(null, { compile: { status: 'unavailable' } })
       } else {
         callback(
           new OError({
diff --git a/services/web/app/views/project/editor/pdf.pug b/services/web/app/views/project/editor/pdf.pug
index 1d550675f3..0c3290053b 100644
--- a/services/web/app/views/project/editor/pdf.pug
+++ b/services/web/app/views/project/editor/pdf.pug
@@ -285,6 +285,10 @@ div.full-size.pdf(ng-controller="PdfController")
 				strong #{translate("server_error")} 
 				span #{translate("clsi_maintenance")}
 
+			.alert.alert-danger(ng-show="pdf.clsiUnavailable")
+				strong #{translate("server_error")} 
+				span #{translate("clsi_unavailable")}
+
 			.alert.alert-danger(ng-show="pdf.tooRecentlyCompiled")
 				strong #{translate("server_error")} 
 				span #{translate("too_recently_compiled")}
diff --git a/services/web/frontend/js/ide/pdf/controllers/PdfController.js b/services/web/frontend/js/ide/pdf/controllers/PdfController.js
index a15fa891ec..3c0eb382f2 100644
--- a/services/web/frontend/js/ide/pdf/controllers/PdfController.js
+++ b/services/web/frontend/js/ide/pdf/controllers/PdfController.js
@@ -462,6 +462,9 @@ App.controller('PdfController', function(
     } else if (response.status === 'clsi-maintenance') {
       $scope.pdf.view = 'errors'
       $scope.pdf.clsiMaintenance = true
+    } else if (response.status === 'unavailable') {
+      $scope.pdf.view = 'errors'
+      $scope.pdf.clsiUnavailable = true
     } else if (response.status === 'too-recently-compiled') {
       $scope.pdf.view = 'errors'
       $scope.pdf.tooRecentlyCompiled = true
diff --git a/services/web/test/unit/src/Compile/ClsiManagerTests.js b/services/web/test/unit/src/Compile/ClsiManagerTests.js
index fc9b79da07..f040e8015e 100644
--- a/services/web/test/unit/src/Compile/ClsiManagerTests.js
+++ b/services/web/test/unit/src/Compile/ClsiManagerTests.js
@@ -214,6 +214,50 @@ describe('ClsiManager', function() {
       })
     })
 
+    describe('with an unavailable response', function() {
+      beforeEach(function() {
+        this.ClsiManager.sendRequestOnce = sinon.stub()
+        this.ClsiManager.sendRequestOnce
+          .withArgs(this.project_id, this.user_id, {
+            syncType: 'full',
+            forceNewClsiServer: true
+          })
+          .callsArgWith(3, null, (this.status = 'success'))
+        this.ClsiManager.sendRequestOnce
+          .withArgs(this.project_id, this.user_id, {})
+          .callsArgWith(3, null, 'unavailable')
+        this.ClsiManager.sendRequest(
+          this.project_id,
+          this.user_id,
+          {},
+          this.callback
+        )
+      })
+
+      it('should call the sendRequestOnce method twice', function() {
+        this.ClsiManager.sendRequestOnce.calledTwice.should.equal(true)
+      })
+
+      it('should call the sendRequestOnce method with forceNewClsiServer:true', function() {
+        this.ClsiManager.sendRequestOnce
+          .calledWith(this.project_id, this.user_id, {
+            forceNewClsiServer: true,
+            syncType: 'full'
+          })
+          .should.equal(true)
+      })
+
+      it('should call the sendRequestOnce method without forceNewClsiServer:true', function() {
+        this.ClsiManager.sendRequestOnce
+          .calledWith(this.project_id, this.user_id, {})
+          .should.equal(true)
+      })
+
+      it('should call the callback with a success status', function() {
+        this.callback.calledWith(null, this.status).should.equal(true)
+      })
+    })
+
     describe('when the resources fail the precompile check', function() {
       beforeEach(function() {
         this.ClsiFormatChecker.checkRecoursesForProblems = sinon