Thermostatic shower mixer valves legislation?

Thermostatic shower mixer valves legislation?

9:03 AM, 31st January 2019, About 4 years ago 9

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Can anyone please pinpoint the legislation requiring landlords to fit thermostatic shower mixer valves in rental properties?

Possibly they are meant to protect vulnerable people in all tenanted properties? Or only required in HMOs? They are meant to greatly reduce the risk of scalding under a too-hot shower.

I was told years ago that they were a legal requirement, and have installed them ever since, but we are having more and more frequent problems with them sticking and not regulating properly. It seems to me that they cannot deal with the very hard water that we get on the edge of the Chilterns/Hertfordshire, and so are getting scaled up with limescale.

Is there a knowledgeable plumber or landlord here that can clarify, please?



Neil Patterson View Profile

14:49 PM, 31st January 2019, About 4 years ago


Requirement G3(3) also extends these hot water safety requirements to vented as well as unvented hot water systems. Entirely new is the requirement in G3(4) that the hot water supply to a bath should be so designed and installed as to limit the temperature of the water delivered to it to no more than 48oC. This requirement applies to baths in new dwellings (including those formed by a material change of use
4consisting of the conversion of a non-domestic building or the provision of a flat in a building). It means in effect that a thermostatic mixing valve (TMV) must be fitted on the water supply to the baths concerned.

Neil Patterson View Profile

14:56 PM, 31st January 2019, About 4 years ago

HSE >>

This guidance aims to help health and social care providers comply with their legal duties.

Hot waterIf hot water used for showering or bathing is above 44 °C there is increased risk of serious injury or fatality. Where large areas of the body are exposed to high temperatures, scalds can be very serious and have led to fatalities.

Hot waterEngineering controls should be provided to ensure that water hotter than 44 °C is not discharged from outlets that may be accessible to vulnerable people and where there is the potential for whole-body immersion. Similar controls may be needed at other outlets where people are especially vulnerable (eg basins where people have skin sensitivity impairment).Engineering controls can include:thermostatic mixing valves (TMVs);■■temperature-restricted, instant water heaters.■■TMVs should be located as close as possible to the outlet, where they are necessary. In healthcare settings, Type 3 is the standard required by the Department of Health’s Health Technical Memorandum 04-01 The control of legionella, hygiene, ‘safe’ hot water, cold water and drinking water systems.1 Type 3 TMVs should be installed when TMVs are replaced or where there are new installations. Further information on TMVs can be obtained from the Thermostatic Mixing Valve Association (TMVA) or at should ensure only safe water temperatures are available. Healthcare standard controls (eg Type 3 TMV or healthcare standard electric showers) and regular safety testing should ensure that the equipment remains safe at all times.Where TMVs are not fitted to baths or showers other equally effective controls should be in place. Locking bathroom doors or removing the hot tap head is not advisable where this will prevent water being flushed out regularly to control the risk from legionella. These measures may only be acceptable in the short term until thermostatic controls are fitted. Where electric showers are fitted, these should be designed so that water cannot be delivered at a temperature that may cause scalding. Domestic electric showers are likely to have temperature regulation features but water temperatures above 44 °C may still occur if there are fluctuations in flow or pressure. If this is the case, and vulnerable people are at risk, additional measures will be required. This may include installing ‘healthcare standard’ showers which are designed to prevent unsafe hot water temperatures under all conditions. NHS standards require these to be fitted in healthcare settings.

What should I do?You should assess potential scalding and burning risks in the context of the vulnerability of those being cared for.A risk assessment of the premises should be carried out to identify what controls are necessary and how the systems will be managed and maintained.The results of the general risk assessment should be taken into account when completing an individual’s care assessment. An individual’s assessment needs to consider whether:the person is likely to try to run a bath or shower ■■or add water when unattended. This is a particular issue for people whose mental capacity is impaired;the person’s lack of mobility means they are unable ■■to respond safely to hot water or surfaces (eg safely get in/out of the bath or shower, or move away from a radiator);the person’s sensitivity to temperature is impaired;■■the person’s mental state means they cannot ■■recognise or react to hot water or a surface that is too hot; the person can summon assistance;■■any lifting or other aids limit mobility in the bath or ■■elsewhere; any furniture, fixtures and fittings restrict movement ■■away from the source of heat.

Neil Patterson View Profile

14:57 PM, 31st January 2019, About 4 years ago

I can't see any specific HMO legislation for Thermostatic shower mixer valves, but I have only just now researched this myself.

Martin View Profile

15:40 PM, 31st January 2019, About 4 years ago

I don't know about the legislation, but I can say that a MIRA thermostatic mixer has worked here for at least a decade in a very hard water area. Worth spending the money on these in my opinion. No affiliation etc..


15:42 PM, 31st January 2019, About 4 years ago

Thanks very much Neil! I think you're right, becaue couldn't find anything in my own searches.
I have just had this response back from a council inspector who checked one of our HMOs today:
"as far as I am aware there is no legislation requiring the installation of thermostatic mixer valves in domestic properties. The only time I have seen these used is in care homes or when we issue disabled facilities grants. So where the user is not able for whatever reason to self-regulate the flow of hot water these may be a wise move."
A caveat is that although this inspector seemed very experienced (and reasonable!), he had just re-entered the workforce (to help the LA cope with all the new HMO applications since 1-Oct-18), so there may be something very recent that he wasn't aware of.
During the inspection, he didn't check the shower controls (four mixers in that HMO), and I don't recall any of his predecessors doing so either, other than to confirm that there was a continuous supply of hot water (that IS definitely a requirement of the HMO regs).

Thanks again!

paul robinson

9:32 AM, 1st February 2019, About 4 years ago

Reply to the comment left by Neil Patterson at 31/01/2019 - 14:49
That wouldn’t likely apply to the post’s properties tho as not retrospective, unless he building a new rental or change of use.

paul robinson

9:40 AM, 1st February 2019, About 4 years ago

I don’t know of any specific rental regulations/requirements, but have always fitted Mira 415 or excel showers and they are still going strong. We are not in a hard water area but if was i’d Likely just service the showers each year, Clean out the filters and replace any parts needed. The service kit are pretty economical to buy, just keep a few in stock ready for when needed.


10:45 AM, 2nd February 2019, About 4 years ago

I have only ever seem these controls fitted in hospitals or care homes. They work by bleeding cold water into the hot water supply and are controlled thermostatically, Interesting that these must be set in the 40 deg C range, yet Legionella regulations require hot water to be stored and supplied at plus 60 deg C.

Jireh Homes

10:22 AM, 3rd February 2019, About 4 years ago

Concur no legislation requiring thermostatic mixer showers in rental properties, and many have electric showers which are often capable of delivering water far in excess of 44 degC . Also many styles of thermostatic showers do not have a safety stop (38/40 degC) so present a similar risk. Some new build properties have a TMV on the bath tap, but suspecting this is an interpretation from guidance relating to likes of care homes which have vulnerable persons.

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