Old central heating pump

[OldJake]

Just changed the pump on our central heating. What a difference! It was taking 2 to 3 hours for the radiator in the lounge to warm up and the boiler was making lots of clanging and banging noises.

10 minutes after I powered everything up, the radiator in the lounge was warm. 30 minutes later and it's hot. I reckon it was all being fed by gravity alone.

Anyway, I was looking for pictures on a new pump to see how bad our old one actually is. But I can't find any of the internal workings. Be interested to know what people think. Will the pump in this state have made much difference?

Also, will a new pump running efficiently make the whole system more efficient? i.e. will it potentially be cheaper to run?





Cheers
Andy

 

[dal5band]

Anti-gravity valve

• dal5band
• 2 Mar 2009
• 1

I had a similar experience but not the pump. It was an anti-gravity valve which was bunged up with similar stuff to your pump. The valve had jumper washer which held it closed and the pump pressure was supposed to lift the jumper to open the valve except it was stuck down. So the whole heating flow was going through a few bypass holes in this valve. I just took it out and put a joint in - the heating's been fantastic since. Had to put thermostatic valves on the upstair rads.

 

[OldJake]

Hmm... I wonder if we've got one of those?

Just looking at the stats for out central heating system (Netatmo) and it took 7 hours yesterday for the lounge to get from 16.2 degrees to 19 degrees. It'll be interesting to see how long it takes tomorrow on a full run.

 

[Mottie]

We had one of those valves that the heating engineer removed when we had the system converted to sealed and unvented. I converted to fully pumped about 25 years and I suspect it was fitted originally when a gravity hot water/pumped heating system was installed. Had you had a gravity hot water system fitted in the past?

 

[Gasguru]

That pumps in terrible state and indicates a whole load of problems with the system....it's rotten.
Is is gravity and pumping over or has a leak and being continually topped up with fresh water?

 

[OldJake]

I can't think were it would be leaking. This house was built in the 60s with hot air heating. That was replaced at some point with central heating so most of the pipes are visible. Pretty sure we'd see a leak one way or another. There is a header tank in the airing cupboard. The ball valve on that is dodgy so the overflow on the outside of the house drips. There is an isolation valve on there and I shut that off at one point. It's a small tank and it will empty but it takes months. I've got a new valve for it but it's in a bugger of a location, about 4 inches from the ceiling so it's not going to be a quick job.

Not sure about it pumping over. Bear in mind this is at least 21 years old as that's how long my other half has lived here.

 

[Gasguru]

If the float valve has been dripping for significant time then the water in the header tank will be fresh and you will possibly get an interchange of water from the header tank to the water in the rads etc.
It depends on the volume of the water in the feed pipework.