I've been putting in a new bathroom and moving some pipes etc. Now everything is connected, when the toilet is flushed and the stop cock in the cistern stops the water filling it, the combi boiler fires up as if a call for hot water has been requested. It stops after about 20-30 seconds. It doesn't happen when the cold tap on the sink is used, which feeds to the toilet.
The only changes to the pipes I have made, apart from moving them around, is to take the cold water feed to the bathroom directly from the main feed from the house supply from under the kitchen sink, where as before, the feed went up into the roof, through a loop where the immersion etc used to be, and then back down to the bathroom. Seemed a bit silly to me to have water going up the house then down. It's an old house so the bathroom is at the back of the kitchen, right next to where the boiler is connected and the water supply to the house.
I assume the sudden pressure change when the cistern stops filling is forcing water through the hot water circuit or something and I need a check valve somewhere.
Can anyone advise what I can do?
Thanks.
The only changes to the pipes I have made, apart from moving them around, is to take the cold water feed to the bathroom directly from the main feed from the house supply from under the kitchen sink, where as before, the feed went up into the roof, through a loop where the immersion etc used to be, and then back down to the bathroom. Seemed a bit silly to me to have water going up the house then down. It's an old house so the bathroom is at the back of the kitchen, right next to where the boiler is connected and the water supply to the house.
I assume the sudden pressure change when the cistern stops filling is forcing water through the hot water circuit or something and I need a check valve somewhere.
Can anyone advise what I can do?
Thanks.