No domestic hotwater

The system:

* Boilermate II thermal store
* Cold water supply for the domestic hot water runs through a LIFF Limefighter "softener" which has not been replaced in 10 years and is weeping a little. The cold water taps do not draw water through this device.

The symptoms:

* Central heating working fine. Plenty of hot radiators
* Quite a lot of "bits" coming through the hot water taps
* Hot water taps run hot for a few seconds and then run tepid
* Hot water had been fine, so it was a step change to not working rather than a gradual deterioration.
* The hot water outlet from the BM II is very hot even when hot taps are running tepid.

My thoughts: I think the mixer value has become jammed with scale/debris from the LIFF limefigter which is breaking up due to being at the end of its life.

My Plan: Buy a new LIFF Limefighter and fit it (I would take it out altogether but that would require more plumbing to join up the ends - we now have a "proper" water softener so I don't see the need for the LIFF). Remove the mixer value and attempt to back flush. Refit mixer value. Cross fingers. Still not working then replace the mixer value.

Have I overlooked some other possibility? Needless to say my good lady is keen for me not to waste time if I'm going to end up needed the "professionals" anyway.

Regards
Ian

Hi Ian,

Sounds to me as though the blender valve has failed. Often associated with installation of a proper water softener as the soft water dissolved the existing limescale and particles loosen and detach and can enter the blender. Usually they just clog up the blender inlet though!

I'd suggest removal of the blender and replacement if not bunged up with scale debris. Cleaning out the scale debris *may* not work either though, as these blenders are quite fragile and prone to failure from dirt ingress.

I very much doubt if the Liff Limefighter is disintegrating inside. They just contain strong magnets AFAIK.

Cheers, Mike

IanNeall wrote:The system:

* Boilermate II thermal store
* Cold water supply for the domestic hot water runs through a LIFF Limefighter "softener" which has not been replaced in 10 years and is weeping a little. The cold water taps do not draw water through this device.

The symptoms:

* Central heating working fine. Plenty of hot radiators
* Quite a lot of "bits" coming through the hot water taps
* Hot water taps run hot for a few seconds and then run tepid
* Hot water had been fine, so it was a step change to not working rather than a gradual deterioration.
* The hot water outlet from the BM II is very hot even when hot taps are running tepid.

My thoughts: I think the mixer value has become jammed with scale/debris from the LIFF limefigter which is breaking up due to being at the end of its life.

My Plan: Buy a new LIFF Limefighter and fit it (I would take it out altogether but that would require more plumbing to join up the ends - we now have a "proper" water softener so I don't see the need for the LIFF). Remove the mixer value and attempt to back flush. Refit mixer value. Cross fingers. Still not working then replace the mixer value.

Have I overlooked some other possibility? Needless to say my good lady is keen for me not to waste time if I'm going to end up needed the "professionals" anyway.

Regards
Ian

The problem is now fixed. As Mike suggested the Liff "softener" was not the issue. For anyone interested, the Liff softener has a blue plastic body and a strong magnet encased in plastic contained in the middle of it. It has no moving parts and as far as I can see can not deteriorate unless it looses it magnetism. The one fitted to the boliermate needs to be the "h" flavor meaning High temperature because although its on a cold water line you can get enough conduction back from the thermal store to get above the max temperature recommended for the "cold" flavor.

Now onto the real problem. The mixing value, Oventrop Brawa , had disintegrated internally. Really it was amazing to see how little there was left of it. Here is a picture of the gory details (Sorry I could work out how to get it to appear inline). The "bits" that we got coming through the hot water were clearly the fragments of the internals (and the disintegrating black fiber washes). If you buy a new mixer value then they do come with new fiber washes, which will likely break when you remove the old value. I managed to make some out of old bicycle inner tube so I could refit the old value, until the new value came. (And by the way, mine came with the a green top - not the white one as I expected for the part part 448-373-0002 - I think the other part 448-373-0001 is the same except it has a "lockable" cap for fitting in places where unwanted hands can fiddle with it)

So I hope this is useful to someone and thanks Mike for the sanity check.
Regards
Ian

Found this post two days after organising a plumber to come and sort out my poor hot water problems (same symptons as listed here). Needless to say, I cancelled him and ordered the mixer valve from the advertised link, the next day it arrived and 25 minutes later we had piping hot water again - I couldn`t believe how easy it was to replace.

Anyone who has a this system and is getting poor or no hot water, don`t delay, order one through the link straight away!!! Don`t try your local merchants as they haven`t a clue (!!), out of the 6x that I tried, no-one could match the price and delivery time of these guys (one of the `big name` merchants quoted me 7-10 days delivery, £120+vat + £10 delivery + non trade excess).

Thanks from a very happy family!!

Just to say a huge thank you to this site for solving our problems.
Our hot water supply was intermittent at best in the days before Christmas. British Gas man (we have a homecare agreement) came out at a time it was working OK, told us there couldn't possibly be any problems if the heating was working (I knew that wasn't true) and left.
By Boxing Day we couldn't get anything other than a brief supply of tepid water, so I looked on the internet, found this site and realised the mixer valve was probably at fault because we had the same symptoms as others had described. Called out British Gas again, proved the hot water supply was rubbish even though the heating was fine and told the engineer what the problem was likely to be. He agreed it just might be and ordered the part. Came back next day and fixed the problem within minutes.
Am quite convinced he wouldn't have been able to diagnose the problem himself. So thanks!

Hi, Man of Bronze, I've recently successfully replaced my pump PCB (wife had doubts I could!) so I am on a roll. My hot water suffers from similar probs to those described and I am prepared to have a go at the Brawa Mixer Valve replacement procedure. However, I am someone who needs a bit of help by way of a simpleton guide. Your's seems to have gone really well - can you assist? p.s. This is such a great forum - well done Boilerman. regards Des

No worries mate I have just spotted Robins post a bit further down which gives a simple plan. Sorry for posting before reading.