No hot water - inlet pipe cold

[HERTS P&D]

Yes, is the water going in and out of the coil?

Andy

 

[Robert Wooler]

Yes, is the water going in and out of the coil?

Andy

Hi there, when i felt the heat (warm to tough) at both the inlet and outlet i thought the water was going through but restricted, until i spoke to someone else who said out outlet could be pulling hot water in.

So in answer to your question im not too sure

Ive tried it with the cap of the automatic air vent for a while to see of air would escape, i didnt see any, only a tiny trickle of water escaping. As ive mentioned in a previous post, heat is getting though the mid position motorised valve and i followed with a magnet, as it goes up towards the airlock all is fine, it then goes across and its about 3/4 across the magnet pulls, and can even hold itself there on the pipe.

The outlet of the cylinder is cold, it did get warm but that was from the bottom upwards to the outlet of the cylinder, the water in the cylinder will be cold, as i havent been able to heat it for 3 days, and ive used quite a bit in testing, so the amount of cold thats been replaced would of took any heat i had in there away. So in a way i expect the return to be cold as any heat i guess would be lost in there.

I also wanted to know whether i can just bang some cleaner in and leave it in for a couple of days and see if that helps, but if it is a blockage, i would be able to empty it all to fill new

Rob

 

[HERTS P&D]

Turn on the hot water and turn off the heating, then let us know what happens after 1 hr.

Andy

 

[Hugh Jaleak]

Anywhere the magnet attracts, (and especially where it sticks), is likely to be badly blocked up with iron oxide, which will be impeding the flow of water and preventing normal circulation. Afraid, as previously stated, the only solution is to cut the affected section out and replace it. No amount of cleaner will break up that type of blockage unfortunately.

The X100 is inhibitor, used to prevent corrosion within the system. Has the system been drained since this was added do you know?

 

[Robert Wooler]

Anywhere the magnet attracts, (and especially where it sticks), is likely to be badly blocked up with iron oxide, which will be impeding the flow of water and preventing normal circulation. Afraid, as previously stated, the only solution is to cut the affected section out and replace it. No amount of cleaner will break up that type of blockage unfortunately.

The X100 is inhibitor, used to prevent corrosion within the system. Has the system been drained since this was added do you know?

The piece where the magnet attracts is in an area where it would be easy to cut out and replace, i was more worried that this isnt the only place, and if there is a blockage in the actual cylinder then im stuck.

As for X100 i think this was added when i had the pump or automatic valve replaced, i think it was automatic valve because i had no heating and he flicked a lever and got me going until i got the unit replaced. It was just over half drained back then, and we are talking a few years now, my bad

Im just going to do what Andy has suggested and see what happens, but yes cutting it out might be a good idea

Rob

 

[Robert Wooler]

Turn on the hot water and turn off the heating, then let us know what happens after 1 hr.

Andy

Hi there, it's been on now for more than 1hr (around 1hr 20) there has been no change in the tempereture of the pipe going into the cylinder, i haven't tried running the hot tap as yet, i was going to hold off incase there was something you want me to check

The return to boiler pipe from cylinder was cold on the bit near the cylinder but got slight warmer as it came away from the cylinder, it comes away and disappears though the floor of the cupboard, its near the flood area where it was warmer

The pump is very hot, you couldn't touch it, whilst i only had water on at the control pad, my radiators were all on too, by control pad for had radiators set to off

My motorised valve was set to auto and the cylinder thermostat was set to 70

The magnet still shows a pull along the same bit of piping as earlier but less of a pull

Another thing to note, if i try and set the motorised valve to manual, where you slide it back, and then hook it in, it doesnt want to stay, it just pops back out of the little bit of metal that looks like its meant to hook it there, also there is no springiness or want to return of the pin, ive seen other videos where its wanted to spring back, mine has no spring or resistance to it. Also i'm unsure of brand, the label only has serial number motor type

Any feedback appreciated

Rob

 

[HERTS P&D]

If you put the heating on, do the rads heat up?

Andy

 

[Alec_t]

there is no springiness or want to return of the pin

That suggests the valve is stuck on CH. Could be sticking mechanically or perhaps the microswitch in the head is stuck or the return spring in the head is broken.

 

[Harry Bloomfield]

update, i did the magnet test again, and at the part of the pipe i've indicated in poss-block.jpg image, the magnet pulls, infact the magnet holds there, this is before it reaches the bend to come back down and into the cylinder, at entrance into cylinder it feels cold, also the out from the cylinder feels cold and gets warmer the as it disapears under the floor of the cupbload (pic above with red valve), i have the pump on 3 for a bit, in the hope extra flow might move any debris, but i think im screwed.

The magnet sticking, absolutely confirms it - your system is choked up with magnetite / rust from the inside of the radiators. You might try flushing water through, using a hose from the mains, with somewhere fixed up as a drain. You might be able to fix your hose on the actual pipe which is blocked.

Failing that, your only option is to replace the blocked pipe with new and hope that the heating coil in the cylinder is not likewise blocked. Even so, you will need to try to flush the system out. Some people go as far as taking radiators out one at a time and flushing the through outside, one way then the other to get as much debris out as possible. You can also buy system cleaners, which are left in for a while, then flushed out.

Once you have it all sorted out - Don't forget to add inhibitor and keep the system topped up with inhibitor.

 

[terryplumb]

The pipe to coil would need to be blocked solid ,totally . Which is possible but unlikely.
The MPV is obviously not open to DHW port . It's default position under Spring pressure is to DHW.
Robert ,set programmer to hot water only ,unlatch the 3 port valve and it should slowly move under Spring pressure alone to the DHW port. See what the result is . Tell us if the pipe from the 3 port to central heating gets hot and if the spring returns the valve to its default position.

 

[Harry Bloomfield]

Robert ,set programmer to hot water only ,unlatch the 3 port valve and it should slowly move under Spring pressure alone to the DHW port. See what the result is.

Even easier, if he simply turns all the power for his boiler etc. to off, a spring return valve should go to the DHW position.

 

[terryplumb]

Even easier, if he simply turns all the power for his boiler etc. to off, a spring return valve should go to the DHW position.

It won't if he has latched it manually

 

[Robert Wooler]

Hi, Andy yes if i put the heating on the rads heat up

Alec T - They automatic valve is generating heat at both outputs A and B and the same heat, even with what i have just done for Any it generated the same heat on both the A and B outputs and that was with HW only on using the programmer

Harry - flushing might be my only option before cutting it out, it can't do any harm me adding cleaner to the system can it? i will still be flushing it all anyway as there is quite an amount of crap seen already in the expansion tank

 

[Robert Wooler]

It won't if he has latched it manually

i cant get it to latch manually, it just pops back out, but stays where it is, it doesnt spring back, ie if i move it all the way to the left (left is my manual end) and let go nothing happens, if move it all the way to left and then hook it into that metal catch but, after a second it jumps back out

 

[Harry Bloomfield]

Hi, Andy yes if i put the heating on the rads heat up

Alec T - They automatic valve is generating heat at both outputs A and B and the same heat, even with what i have just done for Any it generated the same heat on both the A and B outputs and that was with HW only on using the programmer

Harry - flushing might be my only option before cutting it out, it can't do any harm me adding cleaner to the system can it? i will still be flushing it all anyway as there is quite an amount of crap seen already in the expansion tank

If there is no flow to your cylinder coil, the cleaner cannot do it's job. Rather than waste the cleaner, I would see if you can resolve your flow issue first, then try the cleaner.