Are there any plumbers on here?

[Vormulac]

Hi guys,

I need some advice about our hot water system. We moved into a new house about six months ago and have come to realise that the wiring and plumbing was done by someone with some peculiar ideas about how things should be done. Now the hot water system is pretty new, and supposedly pretty high spec, but the upstairs radiators barely work if at all and if there is a shower running then forget anything else running, it's rather annoying to have three showers but only be able to use one at a time.
A friend of mine has a similar sized house and he looked at the hot water system and said it's identical to the one in his place and they can run everything at once with no problems.

I heard the other day that this might be due to a header tank with low pressure in it and something about pumping it up with a bicycle pump! I don't know if it's a factor, but I found the header tank for sale on the web and from the website it looks like the tank in our system might be installed upside down, would that make any difference to how it operates? I really have no idea.

Any input much appreciated, folks!

V.

 

[mbartlett99]

Hi,
Well I'm no plumber but as a ships engineer I can tell you if you're talking about an accumulator (dumpy cylinder with rounded ends and a 'bicycle pump' fitting on the end) then it should be mounted vertically with the fitting at the top. If this is the case I wonder if air has bled out of it and into your radiators? Have you checked the upstairs radiators for airlock (there should be a small square headed fitting at the top)? You might want to post a photo of your 'header tank' just to check we're talking about the same thing.

Cheers,

 

[Vormulac]

The radiators upstairs have been bled and there was no air that I could detect. What you're saying would seem to confirm my fears about this tank, all the pictures I have seen online have the fitting at the top, but mine has it fitted at the bottom.

 

[sparkymarky]

hi i gave a brief explanation of expansion vessels on this post which you may find useful. link - diagnosing-sealed-heating-system-losing-pressure-t56401.html

what type of boiler do you have, a gas combi? which make? model? kw output? do you know where the filling loop is? give me some details and i should be able to help you out.

even if your system pressure is fine, your friends house cant be compared to your house as you may have different flow rates @ the taps, different pressure, different pipe bore sizes and different flow loss due to longer distances of taps from boilers...ect

hope some of this helps, look forward from hearing from you. mark.

 

[Vormulac]

Hi Mark,

I'll fill in the blanks as best I can, I've taken a couple of pictures although I've only put the links on here rather than faff about trying to embed them.

This is the football tank thing: http://www.flickr.com/photos/22857360@N03/6778202237/

This is the boiler: http://www.flickr.com/photos/22857360@N03/6778202247/ Apparently its output (according to the web) is 9.3-12Kw

There is also a large 'MegaFlo' water heater tank thing, although precisely how it's tied into the whole snake's honeymoon of pipes is anyone's guess: http://www.flickr.com/photos/22857360@N03/6778202331/
http://www.flickr.com/photos/22857360@N03/6778202291/

On the top of the red football (what I've rather ignorantly been referring to as a 'header tank') is a white plastic disk that looks like it might be covering a nozzle or something, on the disk it says Flexcon Sealed Expansion Vessel.

I'm afraid I don't know where the filling loop is, nor indeed what it would look like

Thanks for any thoughts on the subject

V.

 

[jasonB]

Pic is a bit small but it looks like there is not much water pressure in the system, the gauge to the right of the boiler should have the black arrow pointing somewhere in the green area, ideally where the fixed red arrow is, post a larger picture of the gauge to be certain.

J

 

[stevep]

The filling loop is the stainless steel braided flexible connector. Just open the valve on the right of your picture , then slowly crack the left one open. The pressure should now begin to rise. When it is around 1 - 1.5 Bar close the valves. Try that and see how it goes.

 

[Vormulac]

Thanks guys, here is a closer look at the gauge, I've never seen the black needle move above the 'one' mark.

http://www.flickr.com/photos/22857360@N03/6778202275/

I'll see if I can shift that valve on the loop and see what happens. Should the system be off or cold or anything before I try that?

 

[mbartlett99]

Ok.

'Expansion tank' is a pressure accumulator and it is fitted correctly. It works by having a rubber bladder inside which is filled with air (under the plastic disk on the top you'll find a pneumatic valve where you can pump more air in if required). Its purpose is to absorb pressure fluctuations within the system. If the rubber bladder has ruptured it can leak air througout the system - that is why I asked if you've bled the radiators. I don't think this is the cause of your problem though.

Is your pump running ok? Turn your pump off and see if there's any difference in the pressure. Is it making a noise of any sort - that would indicate that it may be airlocked - bleed any air off with the screw on the front - be careful not to undo it completely or you'll have a very bad day!

 

[Vormulac]

There doesn't seem to be any difference in pressure whether the system is running or not, the needle stays around the 'one' mark. It's not noisy that I've noticed, I'll crack the screw on the pump a fraction and see what happens.

ETA: I cracked the screw and it just leaked a little water, no air. I tried turning that valve on the filling loop and sure enough the pressure started to slowly climb on the gauge (and the temp on the boiler started to drop, I suppose the hot water in there was being drawn off). I only raised the pressure to the start of the green section (about 1.5 on the gauge) and then turned on the hot water for a few minutes and then tried running a shower downstairs and one upstairs - both ran hot! Result! I suppose I just need to make sure the pressure stays in the green.

Not sure if the radiators upstairs were working any better - I'll check that this evening.