Just been in loft and noticed header tank on my vented system is hot. I understand that this acts as a feed for heating and expansion when heating water gets hot.
Is this normal for tank to get very warm?
Both the feed pipe and vent pipe are hot but no water coming out of vent.
Never noticed before and had no work done recently although I have a suspected 2 port valve issue as hot tap water always very hot despite no hot water is active. Also waiting on getting a system flush as have hydrogen in rads.
Heating after bleeding works well.
Any thoughts or suggestions hugely appreciated
Thanks
Your correct in that the feed and expansion tanks act as
1, A way of filling the system ,beit heating or hws
2,A way for the system to breath and or expand
Your description doesn't say if your tank is heating or pottable water
My assumption is that your talking about the heating, although you do mention excessive temperatures in the dhws ,Does the header tank have separate feed and expansion or is that pipework combined ? It sounds like you have a "S" type heating system this is where you have 2 or more 2 port valves and 1 heating pump, traditionally heating systems of this type were normally configured pumped ch and gravity fed hot water, normally heated via a back boiler and fire front situated in the lounge, this means that the pump only comes on for the CH ,the dhws is satisfied via gravity ,in that the boiler fires for dhws based on the temperature being lower than its set point,as we know heated water rises and cooler water falls this continues until the thermostat is within 3 degrees +/- 2 degrees.
Heating water for your hot water cylinder was given to you as a bye product of having the heating on,say during winter , the pump would push open a none return valve and heating water would flow through your cylinder until its set point was satisfied
Later installations and better installations practices allowed for what we call "fully pumped" systems, this is where the pump runs for both heating and hot water ,the pump would be switched on when the 2 or 3 port valve actuated to its end stop ,pushing on a microswitch this would send power to the pump and boiler switch live, providing your roomstats setpoint was low enough this would start the ignition sequence and fire the boiler and the pump would circulate water until the set point was satisfied if the roomstat was satisfied the pump will continue to run until it falls below that set point, if however the overheat stat switches off the boiler the live supply is blocked and the pump stops ,this is where your problems start your system is what we call venting over ,essentially the boiler is staying on for a period without the pump the water gets too hot and overflows into it expansion tank ,the problem you have is
1, Why is your pump not working
2, Why is the boiler staying on
Your engineer needs to assess your heating system and check its sequence of operation to see at what point its failing ,this is why proper engineers wont give advice over the phone, because guessing causes accidents,
If nothing else your now wiser in heating and heating systems
Hope this helps 👍🏼
Ps Hydrogen gas in a heating system ,again is a bye product of germs of an organic matter have died ,decomposed and produced the gas ,venting the radiator or radiators will emit a smell like a wet fart but joking apart can be quite dangerous and your right to have it removed ,flushing the system will of course remove all matter and decomposition but more beneficially will replace old water for new water this exchange of water should actually be done every 3-4years this will again remove and debris and allow for correct cleaning and the installation of inhibitors these chemicals will slow the production of sludge and excessive pump and valve wear and tear extending the lifespan of the system, you could go a step or 2 further by adding in during the drain down a magnetic particulate filtration device, this will catch large and small down to 3 microns products which left to circulate will eventually block radiators and boiler heat exchangers now your being proactive and that's a good thing
