Problems with mould as heating turned down?

I've found humidistat extractor fans, with guards over the power switches and passive "passyfier" vents in every room has worked extremely well to stop mould throughout the property.

I have started to take a consumption readings from tenant meters at the landlord checks. Clear evidence if the tenants are not putting the heating on, especially if any damp or condensation cannot be found to be a structural issue/cause for which the LL would be liable.

Reply to the comment left by Tim Rogers at 19/12/2022 - 20:08
I think one of the issues with this is that I can't see tenants not interfering with electrical appliances in an attempt to turn them off if they don't know how much they use.

Is anybody using these things? Heat recovery ventilation units?

https://www.amazon.co.uk/KAIR-RECOVERY-SILENT-EXTRACTOR-ANTI-CONDENSATION/dp/B004VW3RGW/ref=b2b_gw_d_simh_sccl_1/262-1479425-1470927?pd_rd_w=h3KSC&content-id=amzn1.sym.eedfa937-05d5-4b57-a6ef-84fe8caf4a1b&pf_rd_p=eedfa937-05d5-4b57-a6ef-84fe8caf4a1b&pf_rd_r=60B1WB709FKZS1F9B0GS&pd_rd_wg=4yirQ&pd_rd_r=62b38f5c-fc4b-4cfc-b416-c2f852da2495&pd_rd_i=B004VW3RGW&psc=1

https://www.amazon.co.uk/BLAUBERG-Recovery-Decentralised-Bathroom-Ventilator/dp/B09B7X9W6C/ref=b2b_gw_d_simh_sccl_2/262-1479425-1470927?pd_rd_w=h3KSC&content-id=amzn1.sym.eedfa937-05d5-4b57-a6ef-84fe8caf4a1b&pf_rd_p=eedfa937-05d5-4b57-a6ef-84fe8caf4a1b&pf_rd_r=60B1WB709FKZS1F9B0GS&pd_rd_wg=4yirQ&pd_rd_r=62b38f5c-fc4b-4cfc-b416-c2f852da2495&pd_rd_i=B09B7X9W6C&psc=1

I would have thought that telling a tenant that these things recover the heat that you are paying for might result in them being less inclined to turn them off.

If anybody is using them, does anybody know which units perform best?

The tenants must stop putting wet/damp clothes on, or drying clothes in front of the radiators. Where a house is double-glazed and well-insulated, the moisture rises and has nowhere to escape, so it builds up in corners and behind furniture. They must keep windows on vent, and open bathroom windows after showering. If the tenants fail to follow these simple guidelines, see below, then the damp will build up and turn into black spot mould. We include this requirement in the tenancy agreement. Also, leaves of trees left in gutters can lead to water running down the walls and ingressing into the brickwork, causing further damp issues. Again, in the tenancy agreement, the tenants are responsible for clearing the gutters. When inspecting the property, check for signs of the above issues. If you have previous photos from previous tenant inventories showing no signs of damp or black spot mould, then this will support your case. The tenants cannot blame their landlords for this. The tenants are creating these conditions themselves and must stop abusing/damaging the landlord's property and blaming their landlord.

Give this to your tenants:

DEALING WITH BLACK MOULD & CONDENSATION IN YOUR HOME
Winter is often the time when you see a build-up of black mould and condensation in your home. Some people do not realise that condensation and black mould is caused by the daily tasks we all do in the home such as cooking, showering, drying clothes, and breathing. All these activities result in moisture being released into the air; unless it can escape this moisture will condense on cold surfaces and will result in black mould growth.
This information sheet details the causes of condensation and black mould and what you can do to reduce it.
Condensation? Condensation is caused by moist air coming in contact with cold surfaces such as walls, windows, and mirrors. It can also build up in places where there is little air movement, in or behind wardrobes and cupboards.
Condensation can cause dampness and mould within your home which can create a distinctive musty smell.
Black Mould? Black mould is caused by a build-up of condensation. Left untreated this can spread from walls onto furniture, curtains, and clothing. Black mould produces spores which can be harmful. The picture above shows black mould spreading across a ceiling. This is caused by excess moisture in your home.
• Two people active for one day 3 pints Cooking and boiling a kettle 6 pints
• Having a bath or shower 2 pints
• Washing clothes 1 pint
• Drying clothes 9 pints
• Using a paraffin/gas heater 8 pints
= Total amount of moisture produced in your home in one day 29 pints.
Use saucepan lids when cooking. This reduces the amount of water needed and cooks food more quickly.
Without a lid, all the steam you see is a warm moist vapour which will condense on cold surfaces.
Dry clothes outside. If you have to dry inside, don’t dry clothes on radiators.
Dry on a clothes rack in front of a radiator, with the window open. Ensure your tumble drier is vented in.
When taking a bath run the cold water first and top up with hot water. This reduces steam by up to 90%.
Never use mobile bottled gas heaters in your home; these produce a lot of moisture. Cover fish tanks to stop water vapour from being released into the air.
Pets and household plants produce moisture too.
How to reduce condensation & moisture in your home?
VENTILATE your home to release moisture
Open windows in the morning for 15 minutes on opposite sides of your home to release moisture. If you’re at home during the day, keep a window open.

Keep trickle vents open all year round and don’t block air vents.
Keep kitchen and bathroom doors closed when cooking and washing to prevent steam from escaping into colder rooms.
Open windows and use extractor fans if you have them (these cost approx. £5 per year to run) for up to 20 minutes after using the bathroom and kitchen.
Keep your home as clutter-free as possible as this reduces the movement of air in your home to release moisture
Open windows in the morning for 15 minutes on opposite sides of your home to release moisture. If you’re at home during the day, keep a window open.
Keep trickle vents open all year round and don’t block air vents.
Keep kitchen and bathroom doors closed when cooking and washing to prevent steam from escaping into colder rooms.
VENTILATE Keep your home warm
Warm homes suffer less from condensation.
If possible keep your heating on a low setting all day; for example, set your thermostat to 15oC. This is more effective than short bursts of high heat.
Unheated rooms attract condensation. Don’t turn thermostatic radiator valves off; always keep them on a minimum of frost setting.
If you don’t know how to set your wall & radiator thermostats, contact your landlord.
Other ways to reduce condensation
Ensure there is a gap for air to flow behind furniture and walls and don’t position furniture against cold external walls.
Wipe windows daily with a squeegee.
Mop up excess water with paper towels and dispose of the towels when finished.

Reply to the comment left by Lesley Thomas at 21/12/2022 - 19:14
While I agree with 99% of the post, one thing sticks out as odd and possibly not legal:
Under the terms of Section 11 of the Landlord and Tenant Act, 1985, responsibility for the maintenance and repair of external structures, including drains, gutters and external pipes, falls squarely on the shoulders of the landlord.

Reply to the comment left by Beaver at 19/12/2022 - 15:29
There is not a GDPR issue here. GDPR deals with personal data. You would not need to store any personal information to monitor temperature and control heating.