Thermometers Direct

ETI Max Min Greenhouse Thermometer 810-121

(Inc. 20% VAT)
(£10.00 Exc. VAT)
(9 Reviews)
15 in stock, immediate despatch
Product Code
Part Number
ETI Thermometers

ETI Max Min Greenhouse Thermometer

These digital max/min thermometers simultaneously display the actual temperature whilst displaying the max and min temperatures.

Each unit measures temperature over the range of -49.9 to 69.9 °C with a 0.1 °C resolution and is ideal for recording temperatures of grow rooms, growing cabinets, greenhouses, pool houses etc.

The unit is housed in an ABS case measuring 29 x 80 x 180 mm. The instrument incorporates a slot for hanging and is powered by 1 x AA battery (supplied).

range: -20 to 69.9C
resolution: 0.1 C/F
accuracy: 1C
Customer Reviews (9)
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9 Reviews:

A tool from yesteryear...
01 May 2023  | 

I thought this was good until I purchased a SwitchBot bluetooth thermometer/hygrometer. The problem is that it cannot be user calibrated and you only know the absolute minimum and maximum temperatures. In reality, you need to know what is the temperature and humidity in your greenhouse hour by hour and to receive alerts to warn you to adjust ventilation. This kind of min/max thermometer was ok around 100 years ago, but for the same price you can do much better. I can check my greenhouse temperature (and humidity) from my living room armchair. Then decide if I need to pop out and open/close the ventilation or pop the shade over on hotter days. My other big problem is that the calibration is out by around 10C and cannot be adjusted. Sorry, but SwitchBot wins by a country mile.

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30 April 2018  | 


1 of 1 people found this review helpful.
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Time will tell
04 April 2018  | 

Clear to read easy to use and a good price

2 of 2 people found this review helpful.
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Clear and simple
07 October 2017  | 

Easy to use, easy to reset. Does the job nicely

1 of 1 people found this review helpful.
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20 July 2016  | 

Easy to set and to read. I bought this for indoors, not the greenhouse, so the design is a bit clunky. How about producing a max/min for the home? - same function but with smaller, neater casing?

1 of 1 people found this review helpful.
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12 July 2016  | 

I found the goods worked ok once I inserted the batteries. However they do not show the same temperatures. The room temp varies by 0.8C whereas the max and mins are only 0.1C dofferent.
Not that much of a problem as it will all be relative. I am not using them for a greenhouse but to put in inoccipied houses to ensure the temp does not ho too low in winter.

3 of 3 people found this review helpful.
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Works well
15 February 2016  | 

Just as promised. And excellent delivery service,

1 of 1 people found this review helpful.
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20 February 2015  | 

exactly what I want for my Orangery

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Best in less humid environments
17 November 2014  | 

I've used these thermometers in a wide range of glasshouses. They are good value and do the job. However, in very humid / wet glasshouses the sometimes fail - the reset button stops working or the batteries corrode. The battery housing is not very waterproof. That said, they are absolutely fine for most glasshouses!

7 of 7 people found this review helpful.
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Delivery Costs

Shipping And Handling

1st Class post up to 14 days for delivery Long delays due to Covid-19

Carrier Service 1-14 days, is an estimated day of delivery is given when you place a order.

Delivery can be from 8.30am to 6pm

Please note all shipping is PER ORDER , NOT PER ITEM

Next day delivery is extra but we can not be held liable for the carriers delaying the (WEEKENDS AND BANK HOILIDAYS ARE NOT INCLUDED IN WORKING DAYS). Highlands and Islands / IV BT, IM TR 21-25, HS, KA27,28, KW1-3, 5-15, PA20-49, 62-77,61,78,PH17-26, 30-44, 49-50, ZE1-3 postcodes takes 48 hour

We must have the order by 3pm to have a chance of getting the order out the same day ( AS LONG AS GOODS ARE IN STOCK) Next day not available for European Orders

ORDERS OVER £65 POST FREE (Excluding European Orders)

For those orders over £65 we will send Post Free. To 1 address if more then 1 address per order, a delivery charge either £6.96 or £3.60 will be added
Once the parcels have left our premises the responsibility for delivery is with the Royal Mail or our Carrier.

We are not responsible for late delivery's that may of happened once the parcel has left us as we will try and get the parcel out to you as fast as we can. Please contact us if any problems, problems do happen but we are always here to help.
Or if you are still waiting for a parcel (over 10 working days Royal Mail) please let us know so we can sort out the problem.
Orders are dispatched by post / carrier to the name and address you have given to us. If we have received incorrect or inadequate information for the delivery of the goods we cannot accept any liability for late or failed delivery as a result of this.

Delivery Schedule We process your order right away. We will normally send your order to you in 2 - 5 business days . International orders are generally received in under 10 days.
Does not Include Trade Orders OR Purchase Orders

A calibrated thermometer if ordered in error / or not wanted can only be returned upto 14 days after purchase because the certificate has a expiry date

Purchase Orders

We accept Orders from Government based purchases, we regularly supply the following organisations

  • Hospitals, PCT's, NHS Foundation Trusts
  • Police Force, Fire Service
  • Councils
  • Prison Service
  • All British Military Forces

There is £50 minimum order value for purchase order

P&P on all Purchase Orders under £65 (ex Vat) £5.42+VAT
P&P will be free on Orders over £65 (ex vat)

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Payment must be made within 30 days by BACS or Cheque