Requirement for Thermostatic Mixing Valves (TMV's)

[frank999]

I understand Thermostatic Mixing Valves (TMV's) are required in baths and showers in public places, schools, hospitals etc.

Does this apply in Rental properties and HMO's ?

Its obviously good practice, but is there a requirement, and should it not also apply to any hot water taps in bathrooms and kitchens ?

 

[denso13]

and should it not also apply to any hot water taps in bathrooms and kitchens ?

No, the thinking is you can be submerged in a bath (and die of scalding) but the natural reaction is to pull your hand away from things like a kitchen sink.

 

[CBW]

Does this apply in Rental properties and HMO's

Yes if a newly erected dwelling, not required for retro fit or if you renew the bath for example.

 

[frank999]

Very helpful thanks.

(b) formed by a material change of use within the meaning of regulation 5(a) or (b)
What is regulation 5(a) or (b) ?? - am I being a bit thick here, but what regulation is it refering to, part G refers to this in several places, yet itself contains no 5(a) or 5(b).

Am I right to think that any a TMV needs to be near each outlet, ie you could not install one device by the Hot Water outlet of the Cylinder to serve all outlets in a property ... presume it would cause issues with fluctuations in temperature at the actuial outlet, for example showers.

 

[CBW]

Very helpful thanks.

(b) formed by a material change of use within the meaning of regulation 5(a) or (b)
What is regulation 5(a) or (b) ?? - am I being a bit thick here, but what regulation is it refering to, part G refers to this in several places, yet itself contains no 5(a) or 5(b).

I’m not 100% as I couldn’t find it either, but when I asked about materials change previously, I think it means like a barn conversion, etc.

 

[denso13]

What is regulation 5(a) or (b)

Earlier in the Building regs I think;

Meaning of material change of use
5. For the purposes of paragraph 8(1)(e) of Schedule 1 to the Act and for the purposes of these Regulations, there is a material change of use where there is a change in the purposes for which or the circumstances in which a building is used, so that after that change—

(a)the building is used as a dwelling, where previously it was not;

(b)the building contains a flat, where previously it did not;

 

[frank999]

Ahh, thanks for finding ... it isn't very clear on what it refers to.

Whilst on TMV's, are the cheaper models (ie £50) more prone to problems ??

 

[Madrab]

If you are installing TMV's to comply with regulations then it needs to be specc'd to at least the TMV2 (domestic) / TMV3 (NHS) standard.

Thermo valves are a lot cheaper now, now that they have been available for a while.

 

[frank999]

Yes I have seen the TMV'3' noted for NHS installations.

For my sins, and one I am sure I will regret, I have what I think is a Domestic TMV2 purchased from that purveyor of some of the cheaper quality brands - the Kingfisher Group - all fur coat etc, but no where in the substandard literature is there any indication if it is a TMV '2'.

 

[Madrab]

You'll probably find that it will be at least WRAS approved coming from the 'Kingfisher Group' but it does need to specify that it is TMV2 certified for it to be approved.
Can you provide the make/model?

 

[frank999]

Its one of these 'economy' products:
https://www.screwfix.com/p/rize-exp...me/491fv#product_additional_details_container
EAN: 3663602665922
Just spoke to SF, they have gone off to speak to Tech, so waiting a call back.

Of all the TMV's shower mixers in the SF catalogue, non state that they are 'TMV2', only item listwed as such is a separate Pegler valve.

 

[denso13]

TMV2 and 3 are descriptions for TMV's (Thermostatic Mixer Valves) which is what the legislation refers to in earlier posts.

This is a TMV,

Are you now talking about shower mixer valves?

 

[sjmac]

Shower valves can be designated TMV2 or 3, https://www.bing.com/search?q=tmv2+...9b46c820ec2e492f7&pglt=43&FORM=ANNTA1&PC=U531

https://www.screwfix.com/p/triton-benito-rear-fed-exposed-chrome-thermostatic-mixer-shower/9164t

 

[denso13]

Are you now talking about shower mixer valves?

If so, I wouldn't worry about it being TMV2 approved. Bar mixers hot output can be adjusted to a maximum temperature anyway (normally).

 

[frank999]

Thanks for clearing up the confusion, I should have referred back to the regs for guidance on what is required.

Some of the confusion arises as I want a shower mixer with a bath filler tap.

If I understand correctly - the Regs, G3(4), for particular types of dwelling, only apply to baths, not showers, so the supply to a domestic bath must be TMV2 certified and approved.

So a shower mixer 'bar' (without tap outlet) does not necessarily require TMV2 certification - provided it is used for its intended purpose - as a shower mixer only ... however it appears you can buy shower mixer bars with the TMV2 cert - as per the Triton offering above. I note the Rize shower mixer product description is ' Thernostatic Mixer Shower Valve'.

What is common practice where G3(4) applies, 1) to install a separate TMV valve under the bath and have a non thermostatic tap set (regardless of whether the tap set itself mixes or not) or 2) use TMV2 approved 'Bar' shower/bath mixer.

Prices for option 2 seem quite steep.

Can a TMV be installed right at the hotwater draw off of the Cylinder to service all taps, or does each bath need a separate TMV right next to it.

If the TMV needs to be next to the bath, presume the outlet of the TMV connects to the hotwater of the Bath taps, and a the coldwater T's off to supply both the cold water tap and the TMV.