Cold Water Storage Tanks in the Loft
A loft tank feeds the cylinder and, in older homes, the bathroom cold taps.
A loft tank feeds the cylinder and, in older homes, the bathroom cold taps. It is out of sight for decades, which is exactly why it turns up in water quality complaints and ceiling leaks.
What a compliant tank looks like
A close-fitting lid, insect-screened vent and overflow, proper insulation, support across joists and no debris inside.
Why old tanks cause problems
Uncovered galvanised tanks collect dust and worse, and a stuck float valve puts the overflow to work — or the ceiling if the overflow has silted up.
Removal or retention
Convert to mains-fed and the tank goes, freeing loft space. Keep the gravity system and the tank should be brought up to standard instead.
Loft tank inspection points
- Lid, screens and overflow clear and correct
- Float valve operating cleanly without hammer
- Insulation over and around, but not beneath, the tank
Who does the work
- Gas Safe registered engineers — registration 554328
- Worcester Bosch accredited installer
- John The Plumb Ltd, company registration 10026483
Loft tank check or removal
If you have never looked in your loft tank, that is reason enough for a check. Tell us the setup and we will advise.
Questions we get asked
Why is water dripping from the overflow?
A float valve not shutting off. It is a small part but it should be dealt with before it becomes a ceiling.
Should the tank be insulated underneath?
No — leaving the underside open lets warmth from below help protect against freezing.
Can I get rid of the tank?
Yes, by converting the hot water side to mains-fed, provided the incoming supply supports it.