diff --git a/packages/grafana-ui/src/components/Gauge/Gauge.tsx b/packages/grafana-ui/src/components/Gauge/Gauge.tsx
index 460547a4d7e..7be0600292f 100644
--- a/packages/grafana-ui/src/components/Gauge/Gauge.tsx
+++ b/packages/grafana-ui/src/components/Gauge/Gauge.tsx
@@ -113,8 +113,7 @@ export class Gauge extends PureComponent<Props> {
       },
     };
 
-    const numeric = value.numeric !== null ? value.numeric : 0;
-    const plotSeries = { data: [[0, numeric]] };
+    const plotSeries = { data: [[0, value.numeric]] }; // May be NaN
 
     try {
       $.plot(this.canvasElement, [plotSeries], options);
diff --git a/packages/grafana-ui/src/utils/valueProcessor.test.ts b/packages/grafana-ui/src/utils/valueProcessor.test.ts
index 76c18f9e93c..22ecf604dc6 100644
--- a/packages/grafana-ui/src/utils/valueProcessor.test.ts
+++ b/packages/grafana-ui/src/utils/valueProcessor.test.ts
@@ -1,36 +1,62 @@
-import { getValueProcessor, getColorFromThreshold } from './valueProcessor';
-import { getTheme } from '../themes/index';
-import { GrafanaThemeType } from '../types/theme';
+import { getValueProcessor, getColorFromThreshold, ValueProcessor, DisplayValue } from './valueProcessor';
 import { MappingType, ValueMapping } from '../types/panel';
 
-describe('Process values', () => {
-  const basicConversions = [
-    { value: null, text: '' },
-    { value: undefined, text: '' },
-    { value: 1.23, text: '1.23' },
-    { value: 1, text: '1' },
-    { value: 'hello', text: 'hello' },
-    { value: {}, text: '[object Object]' },
-    { value: [], text: '' },
-    { value: [1, 2, 3], text: '1,2,3' },
-    { value: ['a', 'b', 'c'], text: 'a,b,c' },
-  ];
-
-  it('should return return a string for any input value', () => {
-    const processor = getValueProcessor();
-    basicConversions.forEach(item => {
-      expect(processor(item.value).text).toBe(item.text);
-    });
-  });
-
-  it('should add a suffix to any value', () => {
-    const processor = getValueProcessor({
-      prefix: 'xxx',
-      theme: getTheme(GrafanaThemeType.Dark),
-    });
-    basicConversions.forEach(item => {
-      expect(processor(item.value).text).toBe('xxx' + item.text);
-    });
+function assertSame(input: any, processor: ValueProcessor, match: DisplayValue) {
+  const value = processor(input);
+  expect(value.text).toEqual(match.text);
+  if (match.hasOwnProperty('numeric')) {
+    expect(value.numeric).toEqual(match.numeric);
+  }
+}
+
+describe('Process simple display values', () => {
+  const processor = getValueProcessor();
+
+  it('support null', () => {
+    assertSame(null, processor, { text: '', numeric: NaN });
+  });
+
+  it('support undefined', () => {
+    assertSame(undefined, processor, { text: '', numeric: NaN });
+  });
+
+  it('support NaN', () => {
+    assertSame(NaN, processor, { text: 'NaN', numeric: NaN });
+  });
+  it('Simple Float', () => {
+    assertSame(1.23456, processor, { text: '1.23456', numeric: 1.23456 });
+  });
+
+  it('Integer', () => {
+    assertSame(3, processor, { text: '3', numeric: 3 });
+  });
+
+  it('Text', () => {
+    assertSame('3', processor, { text: '3', numeric: 3 });
+  });
+
+  it('Simple String', () => {
+    assertSame('hello', processor, { text: 'hello', numeric: NaN });
+  });
+
+  it('empty array', () => {
+    assertSame([], processor, { text: '', numeric: NaN });
+  });
+  it('array of text', () => {
+    assertSame(['a', 'b', 'c'], processor, { text: 'a,b,c', numeric: NaN });
+  });
+  it('array of numbers', () => {
+    assertSame([1, 2, 3], processor, { text: '1,2,3', numeric: NaN });
+  });
+  it('empty object', () => {
+    assertSame({}, processor, { text: '[object Object]', numeric: NaN });
+  });
+
+  it('boolean true', () => {
+    assertSame(true, processor, { text: 'true', numeric: 1 });
+  });
+  it('boolean false', () => {
+    assertSame(false, processor, { text: 'false', numeric: 0 });
   });
 });
 
diff --git a/packages/grafana-ui/src/utils/valueProcessor.ts b/packages/grafana-ui/src/utils/valueProcessor.ts
index 243904c269c..7bd5e3477ac 100644
--- a/packages/grafana-ui/src/utils/valueProcessor.ts
+++ b/packages/grafana-ui/src/utils/valueProcessor.ts
@@ -7,7 +7,7 @@ import { getColorFromHexRgbOrName } from './namedColorsPalette';
 
 export interface DisplayValue {
   text: string; // How the value should be displayed
-  numeric?: number; // the value as a number
+  numeric: number; // Use isNaN to check if it actually is a number
   color?: string; // suggested color
 }
 
@@ -37,18 +37,25 @@ export function getValueProcessor(options?: DisplayValueOptions): ValueProcessor
       let color = options.color;
 
       let text = _.toString(value);
-      const numeric = _.toNumber(value);
+      let numeric = toNumber(value);
 
+      let shouldFormat = true;
       if (mappings && mappings.length > 0) {
         const mappedValue = getMappedValue(mappings, value);
         if (mappedValue) {
           text = mappedValue.text;
-          // TODO? convert the mapped value back to a number?
+          const v = toNumber(text);
+          if (!isNaN(v)) {
+            numeric = v;
+          }
+          shouldFormat = false;
         }
       }
 
-      if (_.isNumber(numeric)) {
-        text = formatFunc(numeric, options.decimals, options.scaledDecimals, options.isUtc);
+      if (!isNaN(numeric)) {
+        if (shouldFormat) {
+          text = formatFunc(numeric, options.decimals, options.scaledDecimals, options.isUtc);
+        }
         if (thresholds && thresholds.length > 0) {
           color = getColorFromThreshold(numeric, thresholds, theme);
         }
@@ -69,8 +76,22 @@ export function getValueProcessor(options?: DisplayValueOptions): ValueProcessor
   return toStringProcessor;
 }
 
+/** Will return any value as a number or NaN */
+function toNumber(value: any): number {
+  if (typeof value === 'number') {
+    return value;
+  }
+  if (value === null || value === undefined || Array.isArray(value)) {
+    return NaN; // lodash calls them 0
+  }
+  if (typeof value === 'boolean') {
+    return value ? 1 : 0;
+  }
+  return _.toNumber(value);
+}
+
 function toStringProcessor(value: any): DisplayValue {
-  return { text: _.toString(value), numeric: _.toNumber(value) };
+  return { text: _.toString(value), numeric: toNumber(value) };
 }
 
 export function getColorFromThreshold(value: number, thresholds: Threshold[], theme?: GrafanaTheme): string {