Hi All,I have noticed that my combi boiler (Worcester reenstar 25Si/30Si Gas-Fired Condensing combination boiler). I have to top up the pressure once a week. I am assuming that there is a pressure leak some where in the heating/radiator system. I have check for loose fittings around the radiators which I have tightened as required. I have also looked for any obvious leaks around the boiler unit. However I have not found any problems. Are there other areas which I could look at to see if there are any leaks. My biggest concern is that there is a leak in areas behind a wall which I can not get to an this leak could be eating at the wall overtime. My boiler is about 3 years old.Anyone have any other areas which they feel I should look at.
Your Boiler is leaking out of the boiler overflow, thats why you can't find a leak anywhere. It is losing pressure because the water pressure valve has a worn spring, and needs replacing.The overflow pipe is connected to the pressure valve. You have to replace the valve, not the spring. it is a sealed unit.
all boilers have a common malady corrosion and rust. This attacks the tubes and due to constant flow and heat and contraction the boiler tubes needs periodic maintenance. Brush them out or bullet the tubes to remove corrosive build ups if a tube shows a failure plug both ends with expanding rubber plugs. Bad thing here is when you remove one tube from service you put strain on all the others, the plugging is a temporary fix, until an entire tubing rimcut and replacement will be necessary. The keyword to successful boiler life is preventative maintenance. Ounce of prevention save a pocketful of money.
Personally I wouldn't touch a combi, instead I'd buy a system boiler (condensing) for the heating, and a gas fired water heater for the hot water. When a combi goes duff you usually end up with neither heating or hot water, and a tidy bill for the repair, furthermore the hot water delivery rates of most combi boilers is not too good on multiple hot water outlet homes. So if you're thinking of en suite in the bedrooms give the combi a miss. An unvented cylinder is fine but it is dependant on the heating boiler, at least if the boiler broke down you could use the immersion. From experience I would suggest a boiler by Worcester Bosch (but we all have our favourites) For the hot water I would 100% recommend a Rinnai water heater - this will give hot water non stop all day until you turn off the tap. The big adavantage here is that you are not heating up water to be stored in a cylinder - the Rinnai will only heat water instantly on demand. Make sure the guys confirm to the building regulations and fit thermostatic valves etc - if you need the full info your local council Building Control guy will give you the info on what's required. Generally when a new installation is completed the installer will self certify the work to the local council. If the council guy comes round and sees that some works have not been done he could get awkward. Good Luck
Are you doing the checking with the system cold as small weeps will evaporate with the heat on. Also have you checked the top fittings on the rads(vent and plug) as the seal on these sometimes fails,and the isolation valves on the boiler also leak around the bit you turn to isolate the boiler.
