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[Datsun 1200 encyclopedia]


Revision as of 02:13, 5 April 2024; view current revision
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Categories: Heating And Ventilation Systems | Body Electrical System

Heater was optional in the Standard model for most countries. All USA models came with a heater (by law).



Coolant Flow to Heater

Heater Hose Dimension
ID: 13mm
OD: 18mm
Radiator hose inlet
ID: 22.5mm
OD: 27mm(flare 29mm)
Diameter at block end: 26mm
Length: 162mm
Heater hose inlet
ID: 14mm
OD: 16mm(Flare 17.5mm)

20399.jpgAlbum 20399

Australia Assembled

Australian-assembled B110 used a Nissan heater by Smiths. The front cover is fastened with screws instead of clips like the Japan-made heater. The electric are on the opposite side and it uses a different #Heater Cock valve.
8710_5986da83403e1.jpgPost 485790 8710_5986daf90b958.jpgPost 485790

8710_5986dac871472.jpgPost 485790 8710_5986db08052de.jpgPost 485790


1972 USA Owners manual

29378.jpg18   29379.jpg19
Comfort and Convenience

TIP: Pull heater level out to switch fan speeds.

See also: Ventilation

27011-H1000.jpg 27011-H1000_.jpg 18712.jpgAlbum 18712 7561.jpgAlbum 7561 7562.jpgAlbum 7562 14595.jpgAlbum 14595 20399.jpgAlbum 20399 21272.jpgAlbum 21272 27137.jpgAlbum 27137

PUSH control knob 27017-G1000
174_551101d70ce59.jpgUpload click to view


Heater Inspection

Heater core:

  • Leaks (before removing, check for leaks in passenger area, under carpet, on firewall cardboard, etc)
  • Flow (ensure it is not plugged). You can test similar to Template:Radiator
  • Clean out debris in exterior of core

Hoses: Check for cracks, overly soft hoses, tight clamps

Flow valve: ensure it opens & closes easily through entire range. Also check linkage for easy and complete movement (before taking apart)

Air ducts: Ensure they are clean and connected properly

Electrical: Ensure fan spins at both High & Low speed

Coolant Thermostat: Test

Control Mechanism

Dashboard#Facia (Cluster_Lid) close up around heater section
24075.jpgAlbum 24075 27118.jpgAlbum 27118

TEMP (lever with temp switch), MODE (defrost/heater lever)
23997.jpgAlbum 23997

27135-H1000 JAPAN
27161-G1000 < 27161-H1001 HOSE-DEFROSTER < 27161-H1000

ヒーター ブロアー スイッチ Heater Blower Switch

hs1.jpg hs2.jpg hs3.jpg

PULL-FAN (some are blank, others say ('FAN')
2126.jpgAlbum 2126 18902.jpgAlbum 18902

Heater Cock

19456.jpgAlbum 19456 19455.jpgAlbum 19455 6595_4ae944705fd36.jpgUpload click to view 6595_4ae9448c7510f.jpgUpload click to view

also see: photo gallery

Alternative: 1989-1990 Commodore part from Repco can be used for the hose to this version of the heater cock POST non-Japan heater cock
8710_53755e23907af.jpgUpload click to view

Part Numbers

Heater cock

  • X2160-30600, X2161-30600 ASSY-VALVE WATER CONTROL B110 USA $18 USD
  • 27017-B8520 COCK- ASSY-FRONT HEATER 7510- B120

B120 Sunny Truck
18257.jpgAlbum 18257

B110 Coupe/Sedan
19457.jpgAlbum 19457

* 27017-H5000 B210
* 27017-N5000 B210 w/Aircon
Compare to other similar units:
* Datsun 240Z


The heater core is like a small radiator. The heater fan removes heat and blow it into the passenger compartment.

21045.jpgAlbum 21045

Part Numbers

Same part number 1970-1994 1200 sedan/ute/coupe JDM and USDM markets.

B210 is 27013-H5000, so a different part.

Heater Hoses

The heater hoses are 1/2 inch inside diameter hose. However, the original Nissan hoses were thin wall. Standard 1/2 inch hose is thick wall and will work but has to be forced through the firewall grommets.

Also, the original B110 thin-wall hoses were the braided type like this:
1894.jpgAlbum 1894
Original long heater hose is braided. Compare to the rear heater hose, which has been replaced with a plain hose.

Original hose clamps were the wire type. They do not need to be tightened very much; they are only there to prevent the hose from pulling off the metal pipe over the bulged part. These clamps are available from Nissan, but in a pinch other kinds may be used.
27293.jpgAlbum 27293

Outlet (long) heater hose
4847.jpgAlbum 4847 7891.jpgAlbum 7891

Outlet Connector (fits in between the two lower radiator hoses):
21794.jpgAlbum 21794

  • 27051-E0100 CLIP-WATER (2) [for radiator hoses]
  • 08723-12000 CLAMP-HOSE (1) [for heater hose]

Inlet connector fitting (back of cylinder head)
27017.jpgAlbum 27017 174_5daebf1cd9901.jpgPost 492928 174_4bcd2a0ee94ff.jpgPost 312907

Fitting thread is 3/8" BSPT


27021-H1000 HOSE-WATER [to outlet, front of engine] $7.50
* 27078-B2000 CLIP (2) [Fixing hose to air cleaner bracket]
* 08510-51012 SCREW-TAPPING (2)
* 08915-43510 WASHER-PLAIN (2)
27075-H1000 CONNECTOR-WATER OUTLET [lower radiator hose T-connector] $9.97
27070-H1000 CONNECTOR-WATER INLET [rear of cylinder head] $4.13
27020-G1900 27020-H1000 HOSE-WATER [from inlet to cock]  $9.88
X2160-30503 HOSE-WATER [from cock to core] $11.13
B7017-B8500 X2161-30600 X2160-30600 ASSY-VALVE WATER CONTROL $18.17
27363-18200 27363-18001 GROMMET-HEATER (2) $0.53
08723-12000 CLAMP-HOSE (5) $2.40
08723-13600 CLAMP-HOSE (2) $2.57 [fixing hose to cock]

Complete set is about $80: 21501-H1000,21506-H1101,B7017-B8500,27022-H1000,27020-G1900,27075-H1000,B7021-H1002,27363-18001,01555-00841,01555-00281,27070-H1000


21820.jpgAlbum 21820

Late from Oct 1989
* 92402-95W00 HOSE-FRONT HEATER, 5 [outlet (long) hose] NICHIRA B517
* 27363-18200 GROMMET-RUBBER (2)
* 01555-00221 CLAMP (4) 8910-
* 92520-G1900 [for rear portion of hose]
  08120-61228 BOLT
* 92520-G1900 CLAMP 9810- [for strut tower]
  08543-61012 SCREW
* 27078-B2000 CLAMP [to air cleaner bracket]
  08110-61610 BOLT
  08911-10637 NUT
B120 early to Oct 1989
  supercedes 92402-G1601, 92402-G1660, 92402-G1661
* 27363-18200 GROMMET-RUBBER (2)
* 08723-12000 CLAMP (3) -8910
* 08723-12200 CLAMP (1) -8910
* 01553-00013 CLAMP -8910 [clamp to hot air tube]
* 27078-B2000 CLAMP [to air cleaner bracket]
  08110-61610 BOLT
* 9330.jpgAlbum 9330 
  Mid-year B120.
  1. Inlet hose 4
  2. Outlet hose 5
  3. Outlet hose connects to block water pipe
B120 Inlet Hose
* 27020-H1000 HOSE FRONT HEATER, 4 [inlet (short) hose] 7510-8109
* 27070-H1000 CONNECTOR-WATER RETURN 7510-8109
* 27020-G1900 HOSE FRONT HEATER, 4 [inlet (short) hose] 8110-
  27070-H5000 CONNECTOR-WATER RETURN 8110-
* 27022-H1000 HOSE-WATER 
  22104.jpgAlbum 22104  

Alternatively, you can use a Toyota Land Cruiser hose for the small hose from the Heater Core to the Cock Valve

* 02-0648 TOYOTA LANDCRUISER All Engines 4L 6CY 1988 - 1992
  29702.jpgAlbum 29702


By comparison, B210 parts are mostly different to Datsun 1200.

USA B210
27020-H5000 HOSE-WATER
27021-H6200 HOSE-WATER
27020-H6110 HOSE-WATER
27021-H6211 HOSE-WATER
14801-30503 HOSE-WATER,U TYPE
X9525-30082 HOSE-STRAIGHT 
JDM Late B210


Heater was optional, so it is not reuired for safe engine operation. If you wish to remove the heater, how is it done?

  1. Drain engine coolant
  2. Remove heater hose from the fitting behind the cylinder head and plug this fitting with a 1/2" rubber cap
  3. Remove heater hose from the lower radiator hose tee. Plug this fitting with a 1/2" rubber cap
  4. Remove heater from inside car, & plug the two holes in the firewall

Plugs can be purchased at your local auto parts store. They have a selection - just ask!

1/2" plug

Firewall plug

You can either remove the fitting from the back of the head & put a plug in there, or get heater blank off rubbers & plug them both. You can get these from local Auto stores, it is 1/2" heater hose.

20668.jpgAlbum 20668
Heater hose plug for cylinder head (as fitted to no-heater models)

Fitting thread is 3/8" BSPT.

Or the simpler way: Run a new longer hose from front to back of engine.

The most elegant way: Remove both lower radiator hoses and the heater adapter, and replace with a single-piece lower radiator hose.

buy at Bprojects
21794.jpgAlbum 21794


Discussion: POST A-series heater removal

Heater Bypass

If the heater core is leaking, the easiest fix is to bypass the heater. Connect the long heater hose to the back of the cylinder head.


You may leave it this way temporarily or permanently -- the engine runs fine either way. Just depends on whether you need the heater for de-misting the windshield.


  • Maddat sells a Universal Electric Demister Unit which is smaller than the stock unit, so it can be used with an extra-large tunnel
  • Electric heaters, You can use a ceramic heater element in the original 1200 heater box. Or just plug in an el cheapo acccesory car heater as from J.C. Whitney.

Heater Motor & Fan

See Heater Motor


See Heater Wiring

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