Morris Minor Owners Club

Having never come across one of these before and there is one in my new minor, how does it work? Does it have a motor in it? What’s the knob on the front do?

All basic questions but as I say, I haven’t had one before and I’m without the drivers handbook to aid me.

The circular Smiths heaters are very simple in operation. Yes, there is an electric motor in it. The knob turns clockwise to switch the heater fan motor on at a fast speed. Turning it further clockwise slows down the speed of the motor. Turning it fully anti-clockwise turns the heater motor off.
Whether water flows through the heater or not is controlled by a valve at the back of the cylinder head. On earlier cars this is opened and closed by a tap, like a little wheel. Later cars had a different type valve with a push-pull knob under the dash to turn it on and off.

There's more than one Circular heater that was used after-market in the 50s.
Mine is a Tudor and the motor in it is controlled by the separate rheostat on the left of the Speedo. The Smiths one had the knob on the Unit itself.

Yes, but the OP says his heater has a "knob on the front" so I assume it is the standard Smiths round heater.......

There is a deluxe version which case a case around it. It connects to a hole in the floor which enables air from the outside to come through the heater.

has a case around it is what I meant to put.

I have installed this one in my MG. I replaced the original motor with a high efficiency speed controlled computer fan which only draws a fraction of the current. If anybody need an original motor as a spare, they can have it if they cover the postage.
Regards
Declan

myoldjalopy wrote: ↑Wed Sep 11, 2019 1:02 pm Yes, but the OP says his heater has a "knob on the front" so I assume it is the standard Smiths round heater.......

I saw that, I was just saying that mine didn't, but I knew the Smiths did, and implying that there might be others out there too as there were several makes around, because it was a time of cars often not having them as factory fit.
Of course, I've no idea what year his car is, whether it had a factory fit or not. My Minor experience is all SII.

newagetraveller wrote: ↑Wed Sep 11, 2019 1:48 pm There is a deluxe version which case a case around it. It connects to a hole in the floor which enables air from the outside to come through the heater.

Is that the one with the vertical selector lever Car/Screen/Off on the front?
When did the elephant trunk under the bonnet get introduced?

geoberni wrote: ↑Wed Sep 11, 2019 2:34 pm
When did the elephant trunk under the bonnet get introduced?

About 2 years after the upgrade to 1098cc, so circa 1964
.
Going back to circular heaters, some had simple doors so that heat could be directed at the screen instead of the car interior.

geoberni wrote: ↑Wed Sep 11, 2019 2:34 pm

newagetraveller wrote: ↑Wed Sep 11, 2019 1:48 pm There is a deluxe version which case a case around it. It connects to a hole in the floor which enables air from the outside to come through the heater.

Is that the one with the vertical selector lever Car/Screen/Off on the front?
When did the elephant trunk under the bonnet get introduced?

Crikey - this has all got rather confusing...

In answer to your question, Geoberni, no it isn't. It's a modification to the round heaters fitted up to early in Series 5 (i.e. 1098) production, often called the 'recirculating' heater. This is prior to the true 'fresh air' heater with the 'elephant's trunk' introduced around the time mentioned above. So, later versions of the recirculating heater had a short metal duct coming through low down on the bulkhead feeding air in to the cowling around the recirculating heater - unlike the later fresh air type, though, there is little in the way of ram air effect. You can open and close the fresh air intake on these recirculating ones with the small lever that looks like a choke know mounted on the underside of the parcel shelf on the driver's side.

Edward1949 wrote: ↑Wed Sep 11, 2019 2:50 pm

geoberni wrote: ↑Wed Sep 11, 2019 2:34 pm
When did the elephant trunk under the bonnet get introduced?

About 2 years after the upgrade to 1098cc, so circa 1964
.
Going back to circular heaters, some had simple doors so that heat could be directed at the screen instead of the car interior.

Confusinger and confusinger... I'm not sure that any standard-fit heaters had this feature ('simple doors')?

I have learned though that many people have a lot of knowledge about a lot of different types of retro-fit heaters. If anyone's interested on the features of my T2 VW heater, let me know and I'll enlighten you

liammonty wrote: ↑Wed Sep 11, 2019 3:01 pm
Confusinger and confusinger... I'm not sure that any standard-fit heaters had this feature ('simple doors')?

That's what my Tudor has (take a look at the photo I posted above), there's a little door each side.
Door open, toasted leg, door closed, demisted screen.
Either/Or, not both, unless of course you have only 1 open, e.g. driver can see, passenger is warm or vice versa.....

Thanks for the info about the Elephant Trunk too.

Search for: Smiths round heater r250

Well thank you for replies, it makes more sense now.
When the motor is running, does it make a sound? Having had a fiddle, I cannot tell if it’s on or not as there is no sound.
As to the valve, I’ve got the cable operated version but the entire cable, knob and bracket are totally missing, so I am going to hunt for a simple tap whilst I am Stratford Autojumble this weekend.

Would it happen to be this model?

When running the fan motor makes a whirring noise, rising with speed and bearing wear. Silence means it’s not going.

If it works you can also feel air blowing out.

cadetchris wrote: ↑Wed Sep 11, 2019 5:45 pm As to the valve, I’ve got the cable operated version but the entire cable, knob and bracket are totally missing, so I am going to hunt for a simple tap whilst I am Stratford Autojumble this weekend.

The 'simple tap' is much more reliable than the repro cable operated ones which have a bad reputation for early failure.......and its recommended to leave the tap open all year round.

The 'simple tap' is much more reliable than the repro cable operated ones which have a bad reputation for early failure.......and its recommended to leave the tap open all year round.

I've seen this recommendation before......but I'm not sure why. Is it possible to explain the 'risk' please?

The theory is that keeping the valve open provides a little more engine cooling because the water circulates round the rear of the head and block better. Also, when shut for long periods, the lack of flow means the heater matrix can get clogged up with sedimentation and the tap itself can get corroded shut - then when winter comes you are cold! It is also a handy check to see if there is enough water in the cooling system - turn the heater on and if you get hot air, all is good. If not, then you may have coolant loss and soon be overheating!