XK120 heater identification

Awhile back I was the recipient of a Smiths heater passed on from a collection of parts identified as coming from an XK120. The one that came with my '54 XK120, restored and pictured on the right, is similar but different in several ways from the one later received, unrestored, on the left:

xk heater (3)

Aside from the colour difference - a kind of military green v. a bluish grey - “left” features a much deeper core than “right”, and while the covers look physically the same they differ in subtle ways - the T-manifold (missing on left) attaches differently. They’re both labelled “Smiths”, one with a riveted id plate featuring serial and model numbers

xk heater (2)

and the other embossed into the housing without a model number, and no evidence of ever having had a riveted plate

xk heater (1)

motors also different, though the four blade fans are the same

xk heater (4)

I’m fairly certain the heater that came with the car is correct, since it fits into the dash, but what’s the story on the one with the deeper core?

Late Mark V has a similar heater, but that’s not it. On Mark V the hose tubes have a 90 degree bend to point away from each other.
heater 003
heater 002
My guess is it is for a different make and model British car.
Or its the special Canada/Scandinavia/Russia optional model.


My '53’s heater is exactly the same as yours. If the other one is “military green” maybe it’s from a Land Rover? Perhaps Roger could chime in with his thoughts.


Now you are making it hard!
SMITHS were of course a prolific supplier of Automotive Accessories to the British Motor Industry, including Jaguar. And indeed this ‘Round Heater’ was a high volume supply item, to both the accessories after-market trade, as well as to original equipment car manufcaturers. I have a couple SMITHS Catalogues, but space allocated to Heaters is minimal, so not a lot, but as best I can tell this ROUND Style Heater came during XK period in four models based mainly on heating power, the CH.1 (1-1/4kW - recirculating type), CH.2 (2 kw - recirculating type), CH.3 (special features - recirculating type), and CH.4 (2 kw - less blower, heating-ventilator type). XK120, XK140 and early XK150 all received the CH.1. But once you have the basic Model Type, the basic unit could be customised to suit specific applications, which was mostly to do with the clip-on-cover and the warm-air distribution outlets (demisting tubes and heater flaps), plus also the detail and position of the two copper water-inlet pipes, and indeed the studs provided for mounting. This was all internal SMITHS engineering/documentation, that for reasons unknown did not warrant any identification plaque on earlier heaters, but from somewhere around introduction of XK140 did get an identification plaque.

Now the Identification Plaque gives a CODE with one example original to an early 1955 XK140 FHC being CHS620/44 ……., noting FHC heaters were different to OTS/DHC due to their different mounting location/orientation (see also 1 1/4 KW output and 12 volt)

Now another SMITHS Catalogue breaks down differently various sub-models of the CH.1, CH.2 etc main Models, and indeed lists CHS620 (in amongst other CHS3xx, 4xx, 5xx, 6xx and 7xx sub-models)
I have to assume that one aspect of the customisation of this basic 1-1/4KW main model gets us to a more specific CHS620 sub-model. Now presumably there were several more detailed customisations of the CHS620 sub-model, that for the specific early XK140 FHC application was now given a fixed/specific CHS620/44 Part Number. I am guessing, that in the earlier Mark V/XK120 days the range of sub-models and then unique part numbers for specific make/model/variant car applications was a lot simpler with no need yet to affix a plaque advising exact Part Number, but by the time XK140 was introduced a plaque with exact part number was now deemed necessary. To date all confirmed XK120 original heaters have no plaque, but all confirmed XK140 and XK150 heaters do have a plaque, and with different part numbers to suit exact application (which I wont go into here).
But over and above plaque or no plaque, and variations to top cover, pipes, and mounting studs, there are also some age related changes made to the cosmetics, including the SMITHS badge.

But from what I can see, your restored painted bluish/grey heater, does look as far as I can tell to be late XK120 original.
The military green painted heater, with plaque advising CODE FHR2403/02 is indeed a CH.7 model, sub-model FHR2403 which is I think a 2 KW output Circular Heater (not sure this is a later 1950s/1960s heater and catalogues I have are not consistent, nor indeed does the plaque still show output), but you have to guess the FHR2403/02 part number could well be some special military vehicle application given the paint colour, but surely an officers vehicle as I cant see the front-line Land Rovers getting heaters :slight_smile:

But at end of day, I seriously doubt there is much of use/value in this FHR2403 SMITHS heater of use to an XK application , maybe the cover/flaps.


I am impressed, Roger.

Edit: and thank you, Chris and Rob.

My March '53 OTS’s heater is like the one on the right.

My 120 was originally delivered to Florida, according to the JDHT certificate. One might think a car heater in Florida might be a bit superfluous. Was this a standard offering in cars headed to the US?

PS: And the CH prefix in Model type stands for Car Heater - who would have guessed!

By '53 the heater was standard equipment. Mine went to Southern California.

I’ll have a look in the book(s), I remember reading… it might have been as early as '52.


I believe that heaters became standard equipment in 1952. I could dive downstairs to my den and get the exact date, but I am preparing supper and it is time to serve and open the Spanish red!


simply outstanding!

I hope you dont mind if I (later) add a picture of what was described to me as a MKV heater core
(by a fellow who owned and worked upon many Jags, including MKV

Its really heavy, has short vertical outlet pipes, (only about 1/2" long, not cut imo)

The correct identity of It has been bought into question …(possibly even an aftermarket Toyota Landcruiser FJ40)…but it is too old & heavy imo

at any rate, if you cannot ID it, afaic, no one can

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I concur entirely. Mustn’t leave a good red waiting!

I dug up the heater valve this afternoon. It has a date stamped into it. December, 1953. The same month and year the car was assembled.

xk120 heater valve

Smiths Heaters where fitted to some Australia cars even

The answer is readily available, I am not aware of anyone saying otherwise, but all you need to do is refer to the XK120 SPC J.8 on page 63A (so later editions of J.8, not the first edition).


Car Heater may be fitted (so requested optional extra ) from Chassis 660059 to 660910, and from 670185 to 671492). So that says not available in aluminium XK120s, but available as an optional extra from the first steel bodied OTS from around Mar 1950/Sept 1950.

Then from 660911 (Sept 1951) and subs, and from 671493 (Sept 1951) and subs, including all FHC and all DHC, the Car Heater Assembly was fitted as standard equipment.

There were of course some variations over this 1950 to 1954 period, and OTS, FHC, DHC regarding detail of the plumbing and hot air distribution, but the actual main SMITHS Heater Unit remained unchanged at Jaguars C.4387 Part Number level, albeit may be some cosmetic updates.

Interesting discussion. As ever, I’m impressed by the depth of knowledge displayed on this forum! For what it’s worth, my Dec 1950 120 was fitted with a heater at the factory in Aug 1952 along with a Radiomobile 4200 radio and aerial plus wing mirror, for the then princely sum of £59 15s 0d.
In 1998 it had a new heater supplied by XK Engineering, costing £305.75. This is the one pictured below.
Serial number is FHR 2405/5, Model R200 - would this be a 2kw heater?

Is there such a thing as a blanking plate for the rectangular takeoff for the demister vents? My car, of course, does not have those.
BTW, new plastic knobs for the doors can be found on Ebay from Land Rover parts specialists.

I once owned 670660, it had no heater.


Don’t know off hand – my Catalogues don’t give output for later FHR heaters, albeit do list the FHR2405 as being a CH.3 type and 10% more expensive than the CHS.620 as fitted to XK120.

Now Heaters for all XK120 and XK140 OTS/DHC are Jaguar Part Number C.4387, and for XK140 FHC a C.8886/1, and from observation of original examples they are all SMITHS CHS.620 but different /suffix for different mounting arrangements of XK140 FHC cf OTS/DHC.

Early XK150 Heaters are C.8886/1 but also shown as SMITHS CHS.620/48 however I have confirmed two very original 1957 XK150 FHC as both having FHR 2405/5 Model R200 heaters, so my best guess is that given the same Jaguar Part Number and CHS.620 Smiths Part Number, the FHR 2405/5 remains the same 1-1/4kW output, with other reasons for the new Smiths Part Number – maybe the cosmetics, maybe the fan blades/motor and an XK150 will probably have Lucar connectors rather than Bullet Connectors consistent with their revised wiring looms.

But I am guessing – haven’t really examined across whole XK120 to XK150 in detail.

I am wondering what the difference now is in a C.4387 as fitted to all XK120 and XK140 OTS/DHC, and a C.8886/1 as fitted to an XK140FHC and all early only XK150.

Did you have any issues fitting your FHR2405/05 (C.8886/1) into your XK120 originally fitted with a CHS.620/??. (I need to check suffix as per XK140 OTS/DHC that now have a plaque, with XK140FHC initially CHS.620/44 then later CHS.620/48 as still specified for all early XK150).


Roger Payne




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Chris, did the factory installation include cutting a big square hole and attaching a heater box on the scuttle, or did they just attach it to your normal scuttle?
I don’t know that there would be a blankoff plate for the cover, but you could make one, or get a single spout off a Mark V unit and have it point hot air at your feet.
And for that final touch, there is the foil Smiths MA label that goes on the cover in the little bell shaped depression.
I found it listed under Austin Healey 100-4 parts.

Roger, thanks for that info. I had no issues with the fit of the heater. It was already there - I just took it off for a clean up and check over. Good to know it could at least have been off an XK, even though it was probably XK150.