Posted By Paul Leadbetter Tracey From what I have read, the problem is with a particular type of thermostat so your first action could be to check whether that type is installed in any of your properties. I cannot remember the type off the top of my head but I am sure it has been mentioned in some of the news reports. Paul

Posted By Konstanty Budkiewicz Tracy, I have been very suspicious of the water system design inferred in related articles: it relies heavily on the inherent reliability of the related electrical components and an understanding of fault syymptoms. Many houses have simple design where a hot water tank and a cold water tank are present. Water is fed from the cold water tank into the hot water tank to ensure it is always full. If the thermostat goes to max output it overheats the thermal expansion pushes the extra water volume back to a small 20-litre-ish expansion tank that also provides make-up water for the central heating system. If the over-heating of the hot water tank continues, the tank is soon filled; however, before the contents are brought to boiling temperature, the tank over flows and vents outside the house. So in this design any overheating of the water tank is seen almost instantly as a jet of hot water and some steam being ejected out of the eves-mounted pipework of the house. The householder, then turns off the water heater and the expansion tank cools until repair of the thermostat takes place. From the link provided by previous correspondants there is some indication that this design fail-safe feature was not present in the affected property. In this case, the expanded hot water appears (possibly on cost grounds) to feed back to the MAIN cold water holding tank only: this tank has a greater capacity and the ball cock is likely to be set low in the tank. Consequently, although the tank was filling with hot water, there was no immediate overt sign that this was taking place. Hence, as usage varied during each day the tank temperature would fluctuate accordingly (and apparently lead to fatiguing of the tank through heat shock, until it spilt and killed the baby). In these cases, the possible clues to the householder could have been: very hot water at outlets, gurgling from the pipework as it expanded, warm/hot water in the toilet flush process, and warm/hot water in the cold taps plus showers upstairs: downstairs is often linked direct to the mains input and stays cold. That said, one needs an awareness of the symptoms and an understanding of their implications. So what are the likely control measures? Suggest that you get a plumbing expert to survey the properties and conduct a design review of the tank arrangements. Where the design feeds hot water direct to the cold water tank, by all means change the thermostats, but I an concerned that you may not be able to communicate the warning symptoms to your tenants. Suggest that you may be looking at system modification: could be costly. Rather than spend more on this design, you could consider getting rid of hot water tanks and installing combi-boilers. This design removes the need for tanks and provides hot water on-demand. In this GREEN age it is worth noting that they also use some 30% less energy. So you may be able to get funding on your GREEN budget plan. Kon CMIOSH

Posted By peter gotch Hi Tracey. See also http://www.hse.gov.uk/press/2008/e08001.htm I listened to a spokesman from, I think, HVCA on Radio 5 commenting that the base support for tank should extend to at least 150mm beyond tank in each direction to avoid it sagging and splitting. There was another thread about these accidents on the forums earlier in the month. Regards, Peter

Posted By Garry Homer A simple fuse-able link fitted in the head of the immersion heater stops the unit reaching temperatures above the rating of the link. Job done. Some modern heaters already have these fitted.