Apologies if I'm an idiot, but I'm learning not to be.
My central heating circulation pump died, most probably because of all the crap in the system (cleaning/flushing the system is my next project!). I replaced the pump and the two valves either side, which meant that I had to drain the entire system. All went fine eventually and am basking in lovely warmth.... BUT.....
The water coming out of my hot tap is cold.
I have an indirectly-heated hot water tank, which (if I understand correctly) means that the water which circulates round my radiators also goes via a coil of pipe in my hot water tank, heating the water in the tank but not mixing with it - just a heat exchange thing.
Ah, I thought, having done a search here and elsewhere - there's an airlock! Connect cold supply to hot, and blast cold mains water up through the hot line, thus pushing air out. Did that. The water cascading out of the top of my tank and all over my airing cupboard led me to (a) stop and (b) realise that there's no air lock in the hot water supply after all.
So.... Sherlock Holmes-like, I deduce that there is no circulation of CH water going through the coil in the tank, even though it's getting everywhere else in the house. I'm thinking in vague terms (cos I'm now out of my depth) about some kind of airlock in that part of the CH circuit, and that this has something to do with my having had to drain the CH circuit.
Questions for you:
1. Am I right so far?
2. How do I fix it????
Points which may or may not be relevant:
1. I have what I take to be a manual three-way valve next to the hot tank - I hadn't changed it from the MAX position at any time during my blundering, and it makes no difference to the coldness of the water if I do actually change it. I have never really worked out how to use this thing or what it's actually for. NONE of the pipes in the vicinity of the water tank and three-way valve is hot (or even luke-warm) at any time, though the radiator 1m away is toasty.
2. There is some weird fitting next to the three-way valve (sorry, can't figure out which pipe it is, but it's on the pipe on the far side of the three-way valve from the tank). It's a solid cylindrical thing with a small milled knob on top which seems to be immobile. I unscrewed it from the pipe, and though there was water in the pipe, it wasn't pressurised. I have NO idea what that thing does.
3. I changed the dead Grundfos 15/50 pump for a Grundfos 15/60, since it seemed like a fair idea to have a bit more welly - it's running nicely (at position 2, just like the old one was, so power should be no less), so I don't think this is important....?
Thanks sooooo much for getting this far, even if you can't help!
My central heating circulation pump died, most probably because of all the crap in the system (cleaning/flushing the system is my next project!). I replaced the pump and the two valves either side, which meant that I had to drain the entire system. All went fine eventually and am basking in lovely warmth.... BUT.....
The water coming out of my hot tap is cold.
I have an indirectly-heated hot water tank, which (if I understand correctly) means that the water which circulates round my radiators also goes via a coil of pipe in my hot water tank, heating the water in the tank but not mixing with it - just a heat exchange thing.
Ah, I thought, having done a search here and elsewhere - there's an airlock! Connect cold supply to hot, and blast cold mains water up through the hot line, thus pushing air out. Did that. The water cascading out of the top of my tank and all over my airing cupboard led me to (a) stop and (b) realise that there's no air lock in the hot water supply after all.
So.... Sherlock Holmes-like, I deduce that there is no circulation of CH water going through the coil in the tank, even though it's getting everywhere else in the house. I'm thinking in vague terms (cos I'm now out of my depth) about some kind of airlock in that part of the CH circuit, and that this has something to do with my having had to drain the CH circuit.
Questions for you:
1. Am I right so far?
2. How do I fix it????
Points which may or may not be relevant:
1. I have what I take to be a manual three-way valve next to the hot tank - I hadn't changed it from the MAX position at any time during my blundering, and it makes no difference to the coldness of the water if I do actually change it. I have never really worked out how to use this thing or what it's actually for. NONE of the pipes in the vicinity of the water tank and three-way valve is hot (or even luke-warm) at any time, though the radiator 1m away is toasty.
2. There is some weird fitting next to the three-way valve (sorry, can't figure out which pipe it is, but it's on the pipe on the far side of the three-way valve from the tank). It's a solid cylindrical thing with a small milled knob on top which seems to be immobile. I unscrewed it from the pipe, and though there was water in the pipe, it wasn't pressurised. I have NO idea what that thing does.
3. I changed the dead Grundfos 15/50 pump for a Grundfos 15/60, since it seemed like a fair idea to have a bit more welly - it's running nicely (at position 2, just like the old one was, so power should be no less), so I don't think this is important....?
Thanks sooooo much for getting this far, even if you can't help!
