Strange hot water flow issue

[Bretty1984]

Hi All,

I am new here and really hoping for some advice or guidance.

I have an unvented system in the house, so a boiler downstairs and a massive tank in my airing cupboard upstairs.

Over the last few weeks, the hot water flowing from the bath mixer tap has started to slow down to a trickle. The flow to the hot water tap at the sink in our en suite has reduced and the same for the hot water in the downstairs toilet.

However, the hot water at the sink in the bathroom flows fine, as does the hot water at the kitchen sink and the hot water in the shower.

So, initially, I was told it could be faulty gland in the hot tap on the bath. I removed that, checked it, cleaned it and it didn't change a thing. I even swapped over the hot and cold glands and the flow was still the same.

I have tried the simple airlock fixes of covering the tap and turning the mixers to half way but that hasn't worked.

Now, I removed the filters from the en suite tap and the downstairs tap and they were blocked. They had a clear, white grit in them and there was some black fragments in there that were absolutely tiny. I cleaned them both and the downstairs toilet hot water is flowing fine but the ensuite is not. There is no filter that I can see on the bath tap as it is a square modern style tap with no filter where the water flows out.

So, my question is - what the hell is going on?!!! 3/6 hot water outlets had an issue but now that is down to 2/6.
Why is the sink hot water in the bathroom flowing fine but not the bath hot water?
Why is the ensuite hot water sink tap not flowing yet the shower in there does?

I have checked visible pipework for kinks.

I do have someone coming out on Friday but does this sound like there is debris in the system somewhere and might be blocking the flow to these 2or 3 outlets given what I have found in the filters?

If this is the case, is there any chemical that can be added to the system and if so, how do I add it or is the problem more severe and remedy more difficult?

It would be awesome to have some input or insights just so I can get my head around this before Friday as we are planning to move, so spending out loads of money isn't something I want to do right now!


Thanks in Advance!

 

[terryplumb]

Your unvented cylinder is probably the problem, crud from it is blocking taps filters or outlets.

 

[polesapart]

And the hot inlet filter on the TMV behind your bath panel is probably blocked.

 

[Bretty1984]

And the hot inlet filter on the TMV behind your bath panel is probably blocked.

Where would I find that, I've had the bath panel off and can't see anything.

 

[Bretty1984]

Your unvented cylinder is probably the problem, crud from it is blocking taps filters or outlets.

Ok, that makes sense. In all seriousness how would all of that crud be removed? Also, what are your thoughts on 3/6 being blocked?

 

[terryplumb]

Depends on where the crud collects ,taps with narrow water passages / flexible hose tap connectors,taps with filters are all subject to be blocked more so than others.
You may need to replace the unvented cylinder, if the part that is breaking down ,such as an air separator, is inside the cylinder.

 

[Bretty1984]

Depends on where the crud collects ,taps with narrow water passages / flexible hose tap connectors,taps with filters are all subject to be blocked more so than others.
You may need to replace the unvented cylinder, if the part that is breaking down ,such as an air separator, is inside the cylinder.

Ah that would be a right pain to replace it. What's the likely cost of that?

 

[terryplumb]

A lot depends on what part of the country you live in, but the cost would be in the thousands not hundreds.
If it turns out that I am correct,get 3 quotes for comparison.

 

[Bretty1984]

A lot depends on what part of the country you live in, but the cost would be in the thousands not hundreds.
If it turns out that I am correct,get 3 quotes for comparison.

You've got to be kidding me. I really hope it is not that as it's only 11 years old. Why is it that not all six outlets are having issues. Wouldn't that suggest a blockage in pipework as opposed to there being another issue? Sorry, I'm not doubting you, just trying to be positive!

 

[terryplumb]

Your problem is the source of the contamination ,not the actual blockaged taps.
What make / model of unvented cylinder do you have ?

 

[Bretty1984]

Your problem is the source of the contamination ,not the actual blockaged taps.
What make / model of unvented cylinder do you have ?

It's a range tribune he and it's 11 years old.

 

[Bretty1984]

Out of curiosity, what would be the benefit of fitting a system such as mine? We live in a four bedroom detached home. It is by no means large. My in laws and parents have four bedroom houses that are much bigger and both have combi boilers that work for them perfectly well.

I have always been ready and prepared to replace things and I don't mind doing that but given the complexity of the system I now have to use someone who is G3 certified - and I am struggling to find someone who is. Along with this, I am frustrated because of the fact that we are considering moving home in the next 3-6 months (to purchase my inlaws house) - talk about bad timing.

 

[Bretty1984]

Just an update. I have had the bathroom hot tap gland out and I pushed a rod through the pipework for around 1.5-2m and lots of plastic shards came back up. That cleared the blockage there and has allowed the water to flow freely. I then did the same with the ensuite and that is now flowing fine. It is a quick fix and something that might cover us until we move but at least we have hot water flowing now.

The only concern is the part that has degraded....not sure what it is, what it did or what problems it might cause further down the line?

 

[terryplumb]

Unvented cylinders can supply a number of hot water outlets simultaneously with good flow rates, combi boilers tend to struggle to do that.
It's likely that further blockages will occur.

 

[Bretty1984]

Unvented cylinders can supply a number of hot water outlets simultaneously with good flow rates, combi boilers tend to struggle to do that.
It's likely that further blockages will occur.

I am expecting more to occur. Would you happen to how big the part is that is likely to be the culprit?