Well we moved into a new (to us) house and found that the central heating
was not working properly. Heating was fine but no hot water.
It is a Baxi Bemuda back boiler with a hot water rtank on the landing and a
seperate emersion heater (If needed).
We called a plumber that was recomended by the Local Council.
They spent all day sucking air through their teeth and left at 5pm in the
evening saying they were going to have to come back another day as things
were still not right.
They had replaced a few sections of push fit (plactic) pipes with copper and
supplied and installed a very complecated timer( the old one was fine)
The following day i checked the timer and there was some hot water for a
The plumber called to say they were going to come out again " and have
I decided that i was not confident that they new what they were doing and
told them to bill us for the work they had done:-
"Attend to carry out alterations to pipe work. Supply and install new
Copper pipe, fittings,programmer, pattress and cover plate."
Total Cost £513 48p????
We have now had another plumber round who has told us that its the 3 port
valve that needs replacing as when the timer is set to hot water it does not
switch and the water gets very hot increases in pressure and vents into the
overflow tank in the loft.
This new plumber has ordered the part and says that the other plumbers have
a cheek asking so much money for so little work
What is everyones opinions??
A faulty mid position valve may not give you hot water but it will not cause
overpumping (the venting into the tank). Overpumping is a symptom of sludge
in your system or that your pump speed is set too high.
When the new plumber fits the new valve check for overpumping and get it
sorted. You have either misunderstood what your new plumber is saying or he
did not know what he was talking about
As for the old plumber then you have got to write to him disputing his
charges and quality of work and asking for a revised bill.
Simply letting the water drain out will not clear the sludge. Ask the new
plumber to check for you when he drains the system to fit your new 3 port
valve. And make sure that inhibitor is added when he refills the system.
As for the bill, if the three port valve is accessible, see if there is a
manual override or see if there is a tank-stat fitted to the h/w tank on the
landing and turn it up. If you get hot water then ask the plumber to
justify his bill based on the fact he is a proficient tradesman in his
field. It may not sound nice but I can imagine his smile when he heard you
perhaps mention; 'new owner of house and just moved in'. I think he will
have rubbed his hands with glee.
From our own experience, if the valve fails in a closed position then the
micro switch on the valve should remain open and therefore not supply the
pump and boiler with power. On the otherhand if the boiler and pump have
been wired directly from the time switch then there is every reason to
suspect the valve could have failed in the closed position when it should be
open (for hot water to tank) and as a result there is no water flow through
the running boiler and it overheats slightly / blows into the header tank.
Depending on the design of the system there may be a bypass to prevent this
(we use a towel rail for this purpose) but a too high pump setting may
aggravate the pump over. Often 3 way valves have a manual override so the
theory of a faulty valve can be checked quite easily -assuming the valve is
easy to get at. I assume there is not a thermostat fitted to the hot water
tank that has failed or has stuck with the contacts in the open condition
hence not calling for hot boiler water?
Sludge tends to collect in slow moving areas e.g. radiators where as h/w
tank feeds and returns often remain clear because they are used every day
throughout the year. Re the cut out pipes, were they clogged with silt or
clean as a whistle? Being plastic pipe, is the system relatively new or
Sorry to go on a bit Tony, but some plumbers lack basic fault finding skills
and spin out a job on the basis of trial and error just as some garages can
do and the poor owner pays for their mistakes. Once the fault is fixed,
which should be in the next day or so, let the original plumber know as you
dispute his bill and why.
Hot water cylinder has a coiled tube in it. Think of it as just another
radiator but sat in a tank of cold water heating it up. Typically what
happens is when your programmer is set to provide hot water, you're applying
power via a thermostat on the side of the tank to a valve which decides
whether boiler heated water goes to your rads, to this coil in your hot
water cylinder, or both.
If the controller is on, and the tank is colder than the temp set on its
thermostat, the valve should move to a position where hot water will flow
through the cylinder coil, and boiler will fire up and pump hot water round.
So what can go wrong? - and the answer is usually electromechanical:
1. The programmer can fail. Typically this will be the relays in it either
burning out or the contacts burning/pitting. So it *looks* like its working,
you might even hear the click of the relay operating - but there is no power
being switched out of it.
2. The thermostat on the tank could fail, but these are simple crude
bi-metal things so are less likely to go.
3. The valve can have problems. This is more often the electrics of the
valve than the water side of the valve. There is a motor in here that can
fail, and also I've known the microswitches in the valve burn/pit their
contacts. For some valves, you can just change the valve electrics and/or
motor rather than the whole valve unit (which means a drain down).
4. There could be a loose wire/connector somewhere between any of the above.
If I was diagnosing, the first thing I would do is set the programmer to hot
water, and take the cover off the tank thermostat and check for power. If
it's there, I've proven two components and most of the cabling in the first
ten mins and can start looking at the valve and/or the short bit of
cabling/junction box you tend to find close by.
If no power at the stat, you'd suspect the programmer. I'd remove it from
its wiring plate and put a temp wire in its place to bypass it and prove the
fault. Note that it may no longer be possible to obtain a replacement for an
old failed unit - so common sense says you'd put a decent modern 7 day unit
So I'd say an hour maximum to diagnose, and if the programmer WAS faulty,
another hour or two to fit one even allowing for having to sort out wiring
between old and new. Swapping valve electrics about the same. Whole valve a
So my questions would be:
1. What was the first guys's justification for changing pipes etc.
2. What did they think was still "not right" after it seems they got your
water hot again?
3. Why does the next guy think the valve is faulty if you had hot water
after the first guy had finished?
PS - not a plumber, just had both a programmer failure and two valve
electrical failures on my own systems in the past.
For what it is worth I was an apprentice heating engineer.
I qualified with City and Guilds.
We installed Baxi Bemuda as you describe.
I was 21 when I "came out of my time".
I am 59 this year.
Make a man think don't it?
Not having practiced my heating skills for nearly 20yrs can agree with all
that's been posted but it seems strange plastic (hep2o) type piping has been
used in places this seems likes modifications.Also Adam as you say a 3port
valve has no off position IF fitted correctly; in rest it does prevent flow
through one outlet allowing dual flow when energised. (remember 10 houses on
a new site all having valve piped wrong) Plumber got fired.
Like Mr P I started in the 70's and Baxi's were all the rage but most I saw
were gravity hot water with only the "Posh" houses going fully pumped.
This problem seems more like a stat problem than flow but as a sparky at
heart I'm biased.
----- Original Message -----
Sent: Friday, February 19, 2010 10:38 PM
Subject: Re: Advice needed - Expensive Plumbing Bill
The valve can only be stuck in one position if it is not the controls, and
that position must be the CH only position or the water would get hot.
Killing all the power to the valve should allow the spring to pull the valve
to the "rest" position which is the HW only position. If the valve does not
move to the HW position with no power then it has seized and need replacing.
The first plumber should have spotted that.
If the white and grey wires are at 0V when only HW is called for then it is
a seized valve.
In the early 1970s central heating was an optional extra on new builds in
Yorkshire never mind the posh fully pumped setups
On Sat, 20 Feb 2010 18:09:32 +0000, Mr Pounder wrote:
That was when I decided to do my own CH for the first time - 1976. I
thought the installed cost from a plumber was outrageous (nearly
£500-00)especially as we'd just paid £8000-00 for the new house.
Using Ubuntu Linux
Let me think now and try to cast back to what is left of my mind.
I was 15, I was created in 1951.
This must have been 1966.
I was living with mum and dad.... house cost them £3k - semi detached.
This was on my wireless.
We were installing central heating, the Wilson Government was giving out
The customers were paying £250 for the job lot.
Not a bad deal really.
I was the apprentice.
Well Plumber number 2 came and fitted a new valve, check all wiring and
No difference still no Hot water just heating, he appologised and told me
that he is stumped.
He has checked everything else that everyone has mentioned including
checking for sludge etc.
He has spoken to another plumber who thinks it may be the hot water tank
that needs replacing.
He is at night school tonight and will be asking a master plumber there.
What does everyone think?
I recall 2 occasions of a similar problem years ago :
1 The cylinder was faulty this was a different type of cylinder to the norm'
as it did not have a coil inside the tank but what can only be described as
an upside down bucket.(can't remember the name made by IMI Fortic
range).These separated the water by trapping an air pocket in the bucket as
the cylinder filled.The fault was that the bucket had rotted and fallen into
the bottom of the cylinder. If you bled the cylinder feeds you got hot water
for around 1/2hr then as soon as the pump stopped no hot water.
2 Normal cylinder but upstairs on opposite side of house to boiler. worked
fine until house had new wiring for sockets upstairs.
Turned out sparks (not me) had bent feed pipes to cylinder flush with
ceiling to allow wiring.This caused an air bubble to form (over a period of
time) stopping circulation to the cylinder even though the system was
good luck and HTH
Baxi is no longer Baxi.
The original Baxi was in Bamber Bridge, Preston Lancashire.
Long ago closed down.
The bloke next door to me has a 1970s Bermuda.
The one with the chip shop gas fire, the one with the tray that pulls out
from under the boiler.
The tray that the soot used to fall down on.
Just thought I'd mention that.
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