The Telford Tempest Direct 300L Unvented Cylinder (TSMD300) is a high-capacity hot-water cylinder designed for properties with substantial demand, such as larger family homes and suitable light-commercial installations. Its direct-heating design uses electric immersion heaters to heat stored water, while the unvented system supplies hot water at mains pressure when correctly installed and connected. The cylinder is made from duplex stainless steel and has a white outer casing.
Product listings specify two factory-fitted 3kW immersion heaters, a 3-bar working pressure and a 22mm domestic connection size. The dimensions vary between retailer listings: some give 1650mm high by 554mm diameter, while others give 1750–1780mm high by 580mm diameter. Confirm the exact dimensions for the supplied model with the seller and check access, pipework and installation space before ordering.
300L Capacity
Direct Electric Heating
Duplex Stainless Steel
2 × 3kW Immersion Heaters
At a Glance
Cylinder Type
Direct Unvented
Tempest range
Capacity
300 litres
Model code: TSMD300
Immersion Heaters
2 × 3kW
Factory-fitted, as listed
Working Pressure
3 bar
Confirm system conditions with installer
Key Features
300-Litre Hot-Water Storage
The 300-litre capacity offers substantial stored-water volume for properties with high demand. Ask an installer to size the cylinder for the household’s usage, number of bathrooms and expected simultaneous demand.
Direct Electric Heating
This direct cylinder heats the stored water using immersion heaters rather than a boiler connected to an indirect coil. Confirm that the electrical supply and heating setup are suitable for your property.
Two Factory-Fitted Immersion Heaters
Listings specify two 3kW immersion heaters. Check the product datasheet and seller’s package details for the exact supplied configuration and electrical requirements.
Duplex Stainless-Steel Construction
Retailer information describes the Tempest cylinder as manufactured from 2304 duplex stainless steel. Confirm the material specification against the current manufacturer’s documentation for the exact model.
Mains-Pressure Hot Water
Designed for an unvented system supplying hot water at mains pressure. Actual performance depends on the incoming supply and correct system design, so have these checked by a qualified installer.
Unvented Installation Kit
Retailer listings describe supplied items including an expansion vessel and unvented safety components. Package contents can vary by seller; confirm the full list before purchase.
Important Installation Guidance:
This is an unvented hot-water cylinder. Installation and commissioning should be completed by a suitably qualified installer in accordance with the manufacturer’s instructions and applicable regulations. Have the installer confirm the system design, operating pressure, electrical requirements, safety components, connections and available installation space.
Key Specifications
| Product |
Telford Tempest Direct Unvented Hot-Water Cylinder |
| Product Code |
148160, as supplied |
| MPN |
TSMD300 |
| Range |
Tempest |
| Capacity |
300 litres |
| Cylinder Material |
Duplex stainless steel; retailer listings specify 2304 grade |
| Heating Type |
Direct |
| Immersion Heaters |
2 × 3kW, as listed |
| Connection Size |
22mm domestic connections, as listed |
| Cylinder Type |
Unvented |
| Working Pressure |
3 bar, as listed |
| Maximum Supply Pressure |
12 bar, as listed |
| T&P Relief Valve Setting |
7 bar / 90–95°C, as listed |
| Orientation |
Vertical |
| Colour |
White |
| ErP Rating |
C, as listed |
| Dimensions |
Supplied listing: 1650mm high × 554mm diameter. Other retailer listings differ; confirm before ordering. |
| Warranty |
Lifetime cylinder warranty and 2-year component warranty, as listed; annual servicing and other conditions may apply. |
Frequently Asked Questions
Is the TSMD300 a direct cylinder?
Yes. The TSMD300 is listed as a direct unvented cylinder, heated by electric immersion heaters rather than an indirect coil connected to a boiler.
What size are the connections?
Retailer specifications list 22mm domestic connections. The 2.5mm figure in the supplied product information appears inconsistent with these listings, so confirm the connection details with the seller before publishing or ordering.
What are the cylinder dimensions?
The dimensions you supplied are 1650mm high by 554mm in diameter. Other listings give different measurements, including 1750–1780mm high and 580mm in diameter. Confirm the exact dimensions for the specific cylinder before checking fit or access.
The Telford Tempest TSMD300 combines 300-litre storage with direct electric heating for a suitable high-demand unvented system. Confirm the product dimensions, connection details, supplied components and warranty conditions with the seller and installer before ordering.
At GetPlumb, we strive to provide reliable and cost-effective delivery options to our customers. Please review our shipping policy below.
🆓 Free Local Delivery (Orders £100 & above)
We offer FREE delivery on orders £100 or more
for selected local areas.
Eligible Postcodes Include:
- RG*
- SL*
- OX10*, OX11*, OX49*
- HP1*, HP3*, HP8*, HP9*, HP10*, HP11*, HP12*, HP13*, HP14*
- WD*, HA*, UB*, TW*, KT*
- W1* – W9*
- NW*, SW*
Delivery Time: 2–4 working days
Shipping Cost: £0.00
📦 Standard Shipping (Weight-Based Rates)
For orders that do not qualify for free delivery, standard
shipping rates apply based on total cart weight.
- For cart weight between 0–2 kg, the shipping cost is £4.50 with a delivery time of 2–4 working days.
- For cart weight between 2–24 kg, the shipping cost is £9.99 with a delivery time of 2–4 working days.
- For cart weight between 24 kg and above, the shipping cost is £60 with a delivery time of 2–4 working days.
🧱 Block Salt (Harvey’s) – Unit-Based Shipping
This rate applies only to Harvey’s block salt products.
- £7.99 is charged for every 3 items.
- The charge increases by £7.99 for each additional set of 3 items.
Examples:
- 1–3 items → £7.99
- 4–6 items → £15.98
- 7–9 items → £23.97
Delivery Time: 2–4 working days
📏 Large / Long Items (Length-Based Shipping)
For oversized items where the product length is 1.5 metres or more:
Conditions:
- Product length ≥ 1.5 m
- Cart weight ≤ 40 kg
Shipping Cost: £18.00 (flat rate)
Delivery Time: 2–4 working days
Collection from Store
Customers can also choose to collect their order from our store in
Reading, UK, at no additional charge. For any questions regarding shipping, please contact our support team at online@getplumb.co.uk.
