diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4cdb069d..91a7f804 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# unreleased
+
+* BREAKING: Implement RFC 141 - remove unsuitable healthchecks and return a 500 on healthcheck failure ([#193](https://github.com/alphagov/govuk_app_config/pull/193))
+
 # 2.10.0
 * Allow LUX domain on img-src policy ([#191](https://github.com/alphagov/govuk_app_config/pull/191))
 
diff --git a/lib/govuk_app_config/govuk_healthcheck.rb b/lib/govuk_app_config/govuk_healthcheck.rb
index 71e29edd..138b3919 100644
--- a/lib/govuk_app_config/govuk_healthcheck.rb
+++ b/lib/govuk_app_config/govuk_healthcheck.rb
@@ -4,19 +4,16 @@
 require "govuk_app_config/govuk_healthcheck/rails_cache"
 require "govuk_app_config/govuk_healthcheck/redis"
 require "govuk_app_config/govuk_healthcheck/sidekiq_redis"
-require "govuk_app_config/govuk_healthcheck/threshold_check"
-require "govuk_app_config/govuk_healthcheck/sidekiq_queue_check"
-require "govuk_app_config/govuk_healthcheck/sidekiq_queue_latency_check"
-require "govuk_app_config/govuk_healthcheck/sidekiq_retry_size_check"
 require "json"
 
 module GovukHealthcheck
   def self.rack_response(*checks)
     proc do
+      checkup = healthcheck(checks)
       [
-        200,
+        checkup[:status] == :ok ? 200 : 500,
         { "Content-Type" => "application/json" },
-        [JSON.dump(healthcheck(checks))],
+        [JSON.dump(checkup)],
       ]
     end
   end
diff --git a/lib/govuk_app_config/govuk_healthcheck/sidekiq_queue_check.rb b/lib/govuk_app_config/govuk_healthcheck/sidekiq_queue_check.rb
deleted file mode 100644
index 97a0e270..00000000
--- a/lib/govuk_app_config/govuk_healthcheck/sidekiq_queue_check.rb
+++ /dev/null
@@ -1,62 +0,0 @@
-module GovukHealthcheck
-  class SidekiqQueueCheck
-    def status
-      queues.each do |name, value|
-        if value >= critical_threshold(queue: name)
-          return :critical
-        elsif value >= warning_threshold(queue: name)
-          return :warning
-        end
-      end
-
-      :ok
-    end
-
-    def message
-      messages = queues.map do |name, value|
-        critical = critical_threshold(queue: name)
-        warning = warning_threshold(queue: name)
-
-        if value >= critical
-          "#{name} (#{value}) is above the critical threshold (#{critical})"
-        elsif value >= warning
-          "#{name} (#{value}) is above the warning threshold (#{warning})"
-        end
-      end
-
-      messages = messages.compact
-
-      if messages.empty?
-        "all queues are below the critical and warning thresholds"
-      else
-        messages.join("\n")
-      end
-    end
-
-    def details
-      {
-        queues: queues.each_with_object({}) do |(name, value), hash|
-          hash[name] = {
-            value: value,
-            thresholds: {
-              critical: critical_threshold(queue: name),
-              warning: warning_threshold(queue: name),
-            }.reject { |_, val| val.to_f.infinite? || val.to_f.nan? },
-          }
-        end,
-      }
-    end
-
-    def queues
-      raise "This method must be overriden to be a hash of queue names and data."
-    end
-
-    def critical_threshold(queue:) # rubocop:disable Lint/UnusedMethodArgument
-      raise "This method must be overriden to be the critical threshold."
-    end
-
-    def warning_threshold(queue:) # rubocop:disable Lint/UnusedMethodArgument
-      raise "This method must be overriden to be the warning threshold."
-    end
-  end
-end
diff --git a/lib/govuk_app_config/govuk_healthcheck/sidekiq_queue_latency_check.rb b/lib/govuk_app_config/govuk_healthcheck/sidekiq_queue_latency_check.rb
deleted file mode 100644
index 5d7459a4..00000000
--- a/lib/govuk_app_config/govuk_healthcheck/sidekiq_queue_latency_check.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-module GovukHealthcheck
-  class SidekiqQueueLatencyCheck < SidekiqQueueCheck
-    def name
-      :sidekiq_queue_latency
-    end
-
-    def queues
-      @queues ||= Sidekiq::Stats.new.queues.keys.each_with_object({}) do |name, hash|
-        hash[name] = Sidekiq::Queue.new(name).latency
-      end
-    end
-  end
-end
diff --git a/lib/govuk_app_config/govuk_healthcheck/sidekiq_retry_size_check.rb b/lib/govuk_app_config/govuk_healthcheck/sidekiq_retry_size_check.rb
deleted file mode 100644
index f6e915e2..00000000
--- a/lib/govuk_app_config/govuk_healthcheck/sidekiq_retry_size_check.rb
+++ /dev/null
@@ -1,11 +0,0 @@
-module GovukHealthcheck
-  class SidekiqRetrySizeCheck < ThresholdCheck
-    def name
-      :sidekiq_retry_size
-    end
-
-    def value
-      Sidekiq::Stats.new.retry_size
-    end
-  end
-end
diff --git a/lib/govuk_app_config/govuk_healthcheck/threshold_check.rb b/lib/govuk_app_config/govuk_healthcheck/threshold_check.rb
deleted file mode 100644
index 58f0f15f..00000000
--- a/lib/govuk_app_config/govuk_healthcheck/threshold_check.rb
+++ /dev/null
@@ -1,50 +0,0 @@
-module GovukHealthcheck
-  class ThresholdCheck
-    def status
-      if value >= critical_threshold
-        :critical
-      elsif value >= warning_threshold
-        :warning
-      else
-        :ok
-      end
-    end
-
-    def message
-      if value >= critical_threshold
-        "#{value} is above the critical threshold (#{critical_threshold})"
-      elsif value >= warning_threshold
-        "#{value} is above the warning threshold (#{warning_threshold})"
-      else
-        "#{value} is below the critical and warning thresholds"
-      end
-    end
-
-    def details
-      {
-        value: value,
-        total: total,
-        thresholds: {
-          critical: critical_threshold,
-          warning: warning_threshold,
-        },
-      }
-    end
-
-    def value
-      raise "This method must be overridden to be the check value."
-    end
-
-    def total
-      nil # This method can be overriden to provide the total for the check.
-    end
-
-    def critical_threshold
-      raise "This method must be overriden to be the critical threshold."
-    end
-
-    def warning_threshold
-      raise "This method must be overriden to be the warning threshold."
-    end
-  end
-end
diff --git a/spec/lib/govuk_healthcheck/sidekiq_queue_check_spec.rb b/spec/lib/govuk_healthcheck/sidekiq_queue_check_spec.rb
deleted file mode 100644
index b20623c9..00000000
--- a/spec/lib/govuk_healthcheck/sidekiq_queue_check_spec.rb
+++ /dev/null
@@ -1,88 +0,0 @@
-require "spec_helper"
-require "govuk_app_config/govuk_healthcheck"
-require_relative "shared_interface"
-
-RSpec.describe GovukHealthcheck::SidekiqQueueCheck do
-  context "an ok check" do
-    subject { TestQueueCheck.new({ queue: 0 }, 10, 20) }
-
-    it_behaves_like "a healthcheck"
-
-    its(:status) { is_expected.to eq(:ok) }
-    its(:message) { is_expected.to match(/below the critical and warning thresholds/) }
-    its(:details) do
-      is_expected.to match(
-        queues: {
-          queue: hash_including(value: 0, thresholds: { warning: 10, critical: 20 }),
-        },
-      )
-    end
-  end
-
-  context "a warning check" do
-    subject { TestQueueCheck.new({ queue: 11 }, 10, 20) }
-
-    it_behaves_like "a healthcheck"
-
-    its(:status) { is_expected.to eq(:warning) }
-    its(:message) { is_expected.to match(/above the warning threshold/) }
-    its(:details) do
-      is_expected.to match(
-        queues: {
-          queue: hash_including(value: 11, thresholds: { warning: 10, critical: 20 }),
-        },
-      )
-    end
-  end
-
-  context "a critical check" do
-    subject { TestQueueCheck.new({ queue: 21 }, 10, 20) }
-
-    it_behaves_like "a healthcheck"
-
-    its(:status) { is_expected.to eq(:critical) }
-    its(:message) { is_expected.to match(/above the critical threshold/) }
-    its(:details) do
-      is_expected.to match(
-        queues: {
-          queue: hash_including(value: 21, thresholds: { warning: 10, critical: 20 }),
-        },
-      )
-    end
-  end
-
-  context "NaNs and infinities" do
-    subject { TestQueueCheck.new({ queue: 0 }, Float::INFINITY, Float::NAN) }
-
-    it_behaves_like "a healthcheck"
-
-    its(:status) { is_expected.to eq(:ok) }
-    its(:message) { is_expected.to match(/below the critical and warning thresholds/) }
-    its(:details) do
-      is_expected.to match(
-        queues: {
-          queue: hash_including(value: 0, thresholds: {}),
-        },
-      )
-    end
-  end
-
-  class TestQueueCheck < GovukHealthcheck::SidekiqQueueCheck
-    def initialize(queues, warning_threshold, critical_threshold, name = :test)
-      @queues = queues
-      @warning_threshold = warning_threshold
-      @critical_threshold = critical_threshold
-      @name = name
-    end
-
-    attr_reader :queues, :name
-
-    def warning_threshold(queue:) # rubocop:disable Lint/UnusedMethodArgument
-      @warning_threshold
-    end
-
-    def critical_threshold(queue:) # rubocop:disable Lint/UnusedMethodArgument
-      @critical_threshold
-    end
-  end
-end
diff --git a/spec/lib/govuk_healthcheck/sidekiq_queue_latency_check_spec.rb b/spec/lib/govuk_healthcheck/sidekiq_queue_latency_check_spec.rb
deleted file mode 100644
index 78c729fd..00000000
--- a/spec/lib/govuk_healthcheck/sidekiq_queue_latency_check_spec.rb
+++ /dev/null
@@ -1,33 +0,0 @@
-require "spec_helper"
-require "govuk_app_config/govuk_healthcheck"
-require_relative "shared_interface"
-
-RSpec.describe GovukHealthcheck::SidekiqQueueLatencyCheck do
-  subject { TestQueueLatencyCheck.new }
-
-  let(:sidekiq_stats) { double(queues: { test: 10 }) }
-  let(:sidekiq_queue) { double(latency: 5) }
-
-  let(:sidekiq_stats_class) { double }
-  let(:sidekiq_queue_class) { double }
-
-  before do
-    allow(sidekiq_stats_class).to receive(:new).and_return(sidekiq_stats)
-    allow(sidekiq_queue_class).to receive(:new).with(:test).and_return(sidekiq_queue)
-
-    stub_const("Sidekiq::Stats", sidekiq_stats_class)
-    stub_const("Sidekiq::Queue", sidekiq_queue_class)
-  end
-
-  it_behaves_like "a healthcheck"
-
-  class TestQueueLatencyCheck < GovukHealthcheck::SidekiqQueueLatencyCheck
-    def warning_threshold(queue:) # rubocop:disable Lint/UnusedMethodArgument
-      10
-    end
-
-    def critical_threshold(queue:) # rubocop:disable Lint/UnusedMethodArgument
-      20
-    end
-  end
-end
diff --git a/spec/lib/govuk_healthcheck/sidekiq_retry_size_check_spec.rb b/spec/lib/govuk_healthcheck/sidekiq_retry_size_check_spec.rb
deleted file mode 100644
index f17ff680..00000000
--- a/spec/lib/govuk_healthcheck/sidekiq_retry_size_check_spec.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-require "spec_helper"
-require "govuk_app_config/govuk_healthcheck"
-require_relative "shared_interface"
-
-RSpec.describe GovukHealthcheck::SidekiqRetrySizeCheck do
-  subject { TestRetrySizeCheck.new }
-
-  let(:sidekiq_stats) { double(retry_size: 10) }
-  let(:sidekiq_stats_class) { double }
-
-  before do
-    allow(sidekiq_stats_class).to receive(:new).and_return(sidekiq_stats)
-    stub_const("Sidekiq::Stats", sidekiq_stats_class)
-  end
-
-  it_behaves_like "a healthcheck"
-
-  class TestRetrySizeCheck < GovukHealthcheck::SidekiqRetrySizeCheck
-    def warning_threshold
-      10
-    end
-
-    def critical_threshold
-      20
-    end
-  end
-end
diff --git a/spec/lib/govuk_healthcheck/threshold_check_spec.rb b/spec/lib/govuk_healthcheck/threshold_check_spec.rb
deleted file mode 100644
index a4ba7bbc..00000000
--- a/spec/lib/govuk_healthcheck/threshold_check_spec.rb
+++ /dev/null
@@ -1,67 +0,0 @@
-require "spec_helper"
-require "govuk_app_config/govuk_healthcheck"
-require_relative "shared_interface"
-
-RSpec.describe GovukHealthcheck::ThresholdCheck do
-  context "an ok check" do
-    subject { TestThresholdCheck.new(0, 10, 20) }
-
-    it_behaves_like "a healthcheck"
-
-    its(:status) { is_expected.to eq(:ok) }
-    its(:message) { is_expected.to match(/below the critical and warning thresholds/) }
-    its(:details) do
-      is_expected.to match(
-        hash_including(value: 0, thresholds: { warning: 10, critical: 20 }),
-      )
-    end
-  end
-
-  context "a warning check" do
-    subject { TestThresholdCheck.new(11, 10, 20) }
-
-    it_behaves_like "a healthcheck"
-
-    its(:status) { is_expected.to eq(:warning) }
-    its(:message) { is_expected.to match(/above the warning threshold/) }
-    its(:details) do
-      is_expected.to match(
-        hash_including(value: 11, thresholds: { warning: 10, critical: 20 }),
-      )
-    end
-  end
-
-  context "a critical check" do
-    subject { TestThresholdCheck.new(21, 10, 20) }
-
-    it_behaves_like "a healthcheck"
-
-    its(:status) { is_expected.to eq(:critical) }
-    its(:message) { is_expected.to match(/above the critical threshold/) }
-    its(:details) do
-      is_expected.to match(
-        hash_including(value: 21, thresholds: { warning: 10, critical: 20 }),
-      )
-    end
-  end
-
-  context "with a total" do
-    subject { TestThresholdCheck.new(0, 10, 20, 40) }
-
-    it_behaves_like "a healthcheck"
-
-    its(:details) { is_expected.to match(hash_including(total: 40)) }
-  end
-
-  class TestThresholdCheck < GovukHealthcheck::ThresholdCheck
-    def initialize(value, warning_threshold, critical_threshold, total = nil, name = :test)
-      @value = value
-      @warning_threshold = warning_threshold
-      @critical_threshold = critical_threshold
-      @total = total
-      @name = name
-    end
-
-    attr_reader :value, :warning_threshold, :critical_threshold, :total, :name
-  end
-end
diff --git a/spec/lib/govuk_healthcheck_spec.rb b/spec/lib/govuk_healthcheck_spec.rb
index eb87f12c..1c1b79b8 100644
--- a/spec/lib/govuk_healthcheck_spec.rb
+++ b/spec/lib/govuk_healthcheck_spec.rb
@@ -3,10 +3,27 @@
 
 RSpec.describe GovukHealthcheck do
   describe "#rack_response" do
-    let(:response) { described_class.rack_response.call }
+    let(:active_record) { double(:active_record, connected?: true, connection: true) }
+    before { stub_const("ActiveRecord::Base", active_record) }
+
+    let(:response) { described_class.rack_response(GovukHealthcheck::ActiveRecord).call }
 
     it "sets the content type" do
       expect(response[1].fetch("Content-Type")).to eq("application/json")
     end
+
+    it "returns a 200 status code" do
+      expect(response[0]).to eq(200)
+    end
+
+    context "a check fails" do
+      before do
+        allow(active_record).to receive(:connection) { raise }
+      end
+
+      it "returns a 500 status code" do
+        expect(response[0]).to eq(500)
+      end
+    end
   end
 end