Large loft extension underway, temporary roof being installed

The house pictured, located in Croydon, Surrey UK,  was being extended into the loft space.  The loft tanks for the hot water system and radiator header tanks had to be removed to make way for the new accommodation.

Our challenge was to provide a new heating and high pressure cold & hot water system in an 1900mm high cellar, which could replicate the shower performance of the existing powerful pumped tank fed system in the loft.  Furthermore, it should support the use of extra bathrooms in the loft area.

This project raised a number of challenging problems.  We could have fitted an unvented hot water cylinder in the basement but there were height constraints limiting the capacity, and no drainage. 

Unvented cylinders require an emergency discharge which must run downhill.  In the event of an over-pressure or over-temperature situation developing, a valve lifts discharging very hot water at mains pressure.  Clearly this was impossible in a cellar. 

The unvented regulations hint that in extreme circumstances, a metal catchment tank could be fitted in a cellar, together with a suitably rated submersible pump.   Problem is, the water could be discharged at 85C and there aren’t suitable submersible pumpsets available rated to keep working at this high temperature.  Furthermore, after many years of potential inactivity the pump could fail to operate at the critical day and then the cellar would flood.  So this was not a practical option.

DPS Pandora Heatstore

Instead, we looked at a heatstore solution.  This is a large vat of water contained in a shell, which in our case is indirectly heated by the boiler.  The water in the heatstore never changes, it is used purely as an energy storage media.  When hot water is required, a 100Kw rated plate heat exchanger is used via a simple pump to transfer heat into the cold main, instantaneously.

We specified a heatstore from Dedicated Pressure Systems, the recognised experts in this field, and based nearby to Hot Water & Central Heating in Epsom, Surrey.   The DPS Pandora was specified in a custom built configuration to just fit below the ceiling in the cellar and pass down the stairway.  DPS’s Pandora is unique becasue it does not require an overflow connection – which makes it ideal for our location.

Mainsboost accumulator upgrades mains water supply

To ensure the DPS Pandora could achieve the design hot water flowrate, we used a TCWS Mainsboost GC450 accumulator to boost the water supply within the property to a flow rate far superior to that provided by Thames Water.

The nett result is a fantastic shower performance which is somewhat akin to a pressure washer.  Indeed, our technical team inadvertently dropped the mobile shower head and got soaked trying to chase it around the bath.  It then slipped out of our hand and we got a second soaking;  a few choice words were exchanged.

We also had to remove an old balanced flue Potterton boiler from the utility room and fit a new high efficiency Vaillant ecoTEC 637 condensing boiler in the cellar.

New Vaillant 637 and zoning system pipework in cellar

As most boiler installers will tell you, fitting a boiler in a cellar leads to flue problems.  If we had fitted a flue to outside from within the cellar height, it would have appeared in the alley outside just 50mm from the ground level.  This is not permitted because the air inlet could be blocked by leaves in the autumn or snow in the winter (although we still see some fitted in this way) leading to a potentially dangerous situation.  We have seen dropped wells dug into the outside garden but these too do not meet regulations unless they are very large indeed.

Neat flue installation from downstairs cellar

We overcame this problem by extending the flue upwards  into the kitchen, by adapting the rear of an existing kitchen unit.  We removed the unit carefully from under the marble worktop and cut a suitable aperture in the rear, and then reassembled the unit around the flue.  This now discharged outside horizontally at an acceptable height of around 450mm from ground level.

Due to the proximity of the adjacent property, we fitted a neat Vaillant plume management kit (PMK) in black, which took the steam to a height of around 6 metres.

Plume management kit was employed to lift boiler steam to 6m high and direct it away from the neighbouring property

Finally, there was the problem of converting the existing central heating system over to a sealed type using expansion vessels instead of the old loft feed and expansion tank.

On the face of it, this is easy, but once again, the emergency pressure relief pipework is not allowed to pass through a vertical element (in case it gets blocked/ freezes).  And due to the absence of drainage in the cellar, dumping the expansion relief on the floor does not meet good practice or building regulations.

Emergency catchment tank

We approached this problem with two solutions.  Firstly, we fitted a galvanised 180 litre catch tank on the basement floor, so that if the 3 bar expansion relief valve did open inside the boiler, all the potential water in the heating system could be safely contained.

But this would be inconvenient to the homeowner if the tank filled, so we fitted an additional expansion relief valve downrated to 2.5 bar just above ground level to discharge conveniently outside.  In this way, the outside valve should lift before the boiler valve in a fault situation, preventing the catchment tank from ever being used. 

A spare plumbed zone valve bay was left in the cellar for a potential future conservatory extension with underfloor heating, and the existing heating system was divided into two zones with individual Honeywell CM927 radio linked programmable room thermostats.

So all in all, quite an involved job, but completed as per our detailed quotation, and delivered on time.   As usual, our Vaillant boiler installation is backed by a 5 yr parts and labour warranty.

Having transformed the water supply next door, we were invited to carry out the same task on this property.

Crystal Palace, our secret location

A TCWS Charger and mainsboost system was fitted, connected to an existing Gledhill Boilermate III heat store.

Charger & Mainsboost installed in garage

Now all the showers work on all floors. 

Charger/Mainsboost is a specialised water boosting product which utilises the ruling that water can be pumped from the mains at up to 12 litres per minute.  The water authorities are very particular at how this can be done, and in order to get approvals the manufacturer took around two years perfecting the design to prevent any possibility of backflow etc.  Once installed the Charger/Mainsboost can support flow rates of in excess of 40 litres per minute at pressures of up to 4bar…..irrespective of the quality of the supply.

Hot Water & Central Heating are your local and experienced specialists.

Our customer lives in an area of Crystal Palace where the water supplier has in the last 12 months reduced the pressure in the mains.

The secret to successful showering is in the garage

This has resulted in a pressure just above 1bar on the lower ground floor;  this house is on 4 stories and there are bathrooms on the 2nd and 3rd floors.  The result was that the bath took ages to fill, the shower on the 3rd floor could not be used, and the shower on the 2nd floor was poor.

Protests to Thames Water from most of the residents in the immediate area did not result in satisfaction, because they were supplying over the statutory minimum pressure to the bottom floor of the property.

Hot water in these properties is supplied through a Gledhill Systemate III heatstore.

Hot Water & Central Heating were asked to provide a solution for the problem, retaining the existing boiler and heatstore.

We fitted a TCWS Charger and Mainsboost system in the lower floor garage.  This innovative patented unit consists of a pumpset and an accumulator.  The pumpset uses less than 12 litres per minute and incorporates anti backflow protection, enabling it to be connected directly to the water main.

TCWS Charger and Mainsboost in garage

It is very quiet in operation, and charges a large accumulator on a ‘trickle’ basis to replicate the performance of an accumulator on a 3bar main.

The Pump incorporates programming to manage the duty cycle and the maximum/minimum pressure.  Once commissioned, the system needs no further adjustment and will continue to run in a power cut.  If the pumpset fails, an automated bypass allows the mains to still enter the property without user intervention.

If you have a water supply problem, and are in our area (see our main ‘areas covered’ button at the top of the page) we can advise you.

Following commissioning, our customer was very happy with the results, which now means that all bathrooms are fully back in operation.  We have already been asked to provide two other nearby households with quotations for similar systems.

Stop Press:  Following the success of this installation, Hot Water & Central Heating have received an order to install an identical system to the house next door in May 2009.

ºOur customer has a large 3 storey Victorian detached property in Dulwich.

In common with many houses in this area, an old gravity fed hot and cold water system using loft tanks was employed. 

Our customer wished to gradually update his house to new mains pressure fed bathrooms, using European high pressure taps, and wisely didn’t fancy the prospect of shower pumps.

He also wanted to make use of the loft space currently occupied by the large water tanks, and remove the old copper hot water storage cylinder on the 1st floor to make room for another shower.

Our brief was to design the plant to deliver his requirements, all within a cellar a little under 6 feet tall.

In the cellar we found a venerable Kidd Boiler, dating from 1990, so this was retained as it probably has a good few years of life left in it.   Launched in 1982, it was an early condensing high efficiency design that remarkably few ‘heating engineers’ have heard of to this day, even though it was probably the first commercial British condensing boiler.  Still made today, we still fit them!

Kidd Boiler Model 2 Gas (now available in white!)

I commonly hear ‘how reliable’ someone’s old Potterton has been……….  if they had fitted a Kidd instead 20 years ago it would have been just as reliable but burnt just over half the fuel in the intervening 20 years.  Notables including the Highgrove Estate and Peter Gabriel were savvy enough to understand the importance of not wasting fuel back then, but that’s another story….

We had to boost the water flow rate from the 20 litres a minute provided by Thames Water to in excess of 40 litres per minute.  We did this with a stored water pressure vessel.

We then needed a hot water storage system that could fit below the low ceiling, but have a fast recovery time in the event of concerted use.  We looked into a heatstore, but the costs of having a special unit fabricated to meet the space restrictions were very high.  Also the Kidd Boiler does not modulate, so ideally we would need a heatstore with a 46Kw plate heat exchanger to enable the boiler to discharge its power in a long burn, rather than a protracted series of short cycles, which wastes energy needlessly.

We ended up specifying the ACV Smartline tank in tank ‘unvented’ cylinder instead.  To those of you who think of a Megaflo when unvented cylinders are mentioned, this is a World apart.

ACV cylinder cutaway

The stainless steel water cylinder containing your hot water is suspended within another steel cylinder containing the boiler heated water.  When the water is heated it is surrounded 360° by the boiler water, resulting in a very fast warm up time indeed. 

So our Kidd Boiler can discharge it’s full output of 46Kw into the ACV cylinder, resulting in a quick heat recovery period.

The ACV cylinder has another trick;  although it is an unvented cylinder, it is designed to store water at 80ºC, rather than the 60ºC usually used.  The reason we normally store hot water at 60C is that at temperatures above this, limescale is precipitated from the water and deposits scale.  The ACV inner cylinder is ribbed, and every water draw off causes a movement, this prevents scale from building up.  The electrical immersion heater is fitted to the other jacket, so never scales up.

The result is that we can store more hot water energy in an ACV cylinder than an equivalent sized alternative, and most boilers will work more efficiently when driving them. 

Water Boosting Vessel and ACV Smartline hot water unvented cylinder

The equipment was all mounted well below drainage level, so a Drainmaster high temperature compatible pumpset was fitted.  The Kidd Boiler used to disharge its condense into a plastic 2 gallon drum (nobody manufactured condensate pumps in the 80s and 90s, so this was a common bodge), but now it can use the Drainmaster, along with a soon to be fitted sink, washing machine and of course the emergency discharge from the unvented system.  The Drainmaster is a pump in a vented sump, and is hot water rated for these types of application.

The outside Kidd flue had been damaged by builders, so we commissioned a new hand welded item from Kidd Boilers  (Mr Kidd, as usual, had the original installation drawings on file)

Finally, the latest Honeywell programmable room heating controller (CM927) was added to the installation to bring it up to date.

Honeywell Programmable room thermostst

We think the showers are now almost too painful to get under……..  but some of our customers like them like that!

Our client has bought a 1960s house in the well regarded village of Woldingham, Surrey, and embarked on a major remodelling of all services and interiors.

When finished, the building will incorporate a modern kitchen, and comprehensively remodelled interiors.

We have assisted our customer in the selection of the heating system, but they have also contributed much to the specification, including the innovative Jaga Strada ‘low H20′ high efficiency radiators.

HWCH will be fitting a large underfloor heating grid on the ground floor, a 46Kw Viessmann 200 series light commercial boiler, accumulator boosted DualStream hot and cold water system, all controlled by the Honeywell Hometronic radiator and underfloor control system.

The industrial gas meter has been moved as part of the works, and our commercial gas engineer will be installing a new underground service to the house and swimming pool boilers.

Work is expected to finish in early 2009, but for now,here are some photographs;

Viessmann 46Kw boiler in utility room

Part of the underfloor heating grid just installed

Cylinder cupboard 35mm pipework under test

This job was in a large house which had two open flued water heaters on the 1st floor providing hot water to the bathrooms.

Our customer wanted the old gas appliances removed for safety reasons, and also desired a mains pressure system to feed his new baths and showers, instead of the noisy and unreliable pumped system.

We recommended a DualStream accumulator fed unvented system.  The accumulator (which boosts the available water flow rate in the house) was fitted in one airing cupboard, and a 300 litre unvented cylinder was fitted in the other.

DualStream accumulator in one airing cupboard

The accumulator fed system discharges water at an enormous flow rate into the showers and baths. 

Shaun puts the finishing touches to the DualStream unvented HW cylinder

In fact, it quickly exposed a faulty plastic pipe joint fitted by another bathroom installer.  After a quick pop up the system was fully operational.

Vaillant EcoMax Pros in basement

The new system was adapted to run off a pair of existing Vaillant open vented Ecomax Pros in the basement.  One of these was not working but it was a simple arcing electrode fault. 

We rewired these units to work with the Honeywell Hometronic radiator management system, now our customer has full control of 16 different zones of heating.

Our client had a delightful detached house in a secluded road in Oxted, Surrey.

The house had been extended into the loft, and had ended up with three luxury bathrooms.  Unfortunately, the hot water storage cylinder was jammed under the stairs and was too small.  And there were three separate shower pumps (each installed by plumbers with every new bathroom).

The shower pumps were noisy, one was a negative head type (so it suffered from running for short periods in the middle of the night), the hot water cylinder could not be sited anywhere else, and the water tanks took up valuable space in the eaves.

The boiler was an old Potterton Kingfisher light commercial 60Kw unit, mounted in an external boiler house.  Our customer wanted to remove the water tanks and cylinder from the house, and relocate everything into the small outside boiler cupboard.

And she wanted the boiler flue of the new unit to go up the existing chimney.

With this set of rather onerous requirements, there were a shortage of heating and plumbing companies with suitable solutons.

The old boiler was from heat calculations, considered to be oversized at 60Kw.  In fact, a 35Kw boiler would deliver a more than adequate heating performance for the property. 

We estimated that the hot/cold water requirement would be circa 40 litres per minute.  We choose the ACV Heatmaster combination boiler unit, because this can deliver this incredible flow rate into a domestic property.

Most unvented cylinders struggle to deliver this kind of performance, and here we have a combined boiler and hot water generator that can cover all the bases in one simple unit.  Truth is, whilst the ACV is billed as a combination boiler, it is really a hybrid solution, being a croos between a heatstore and an unvented cylinder.

It uses the trusted ACV tank-in-tank technology, and can run in full condensing (high efficiency) mode even when producing hot water.  The heatstore runs at 85C and directly heats the house and indirectly heats the hot water, in an enveloped tank.

The ACV was adapted to run ‘open flue’ up the chimney.  Our customer needed some roof repairs so the scaffolding for the twin walled condensing smooth liner was shared between HWCH and their roofing contractor.

Of course, running a mains fed water system to serve three bathrooms requires a good quality water main. 

In common with most houses, our customer’s water main struggled to deliver 22 litres per minute, and we were looking for closer to 50 litres per minute when those three bathrooms were being used.

To improve the peak water flow rate, a GAH accumulator was fitted in the boiler plant room directly behind the ACV Heatmaster. 

It was a tight fit in there, but what a performance punch we packed in!

Instantaneous hot water, fully condensing performance, boosted water flow, three bathroom showers at the same time, and no plant inside the house.  On time, and on budget.

Second problem is, the tank is atmospherically open, leading to potential contamination and stagnation issues.  Particularly as the location tended to be quite warm most of the year.

HWCH were aproached for a better solution, even though the original had only been in place for a few years.

Our client, a farm near Tadworth, Surrey, had an older boiler running two gravity hot water cylinders.

Our customer in Tadworth - not the dog!

The spacious house had a fully equipped annexe with its own hot water provision.

We specifified two DualStream accumulator fed systems, which would replace the old noisy shower pumps and provide a silent, fast flow fresh water service to all outlets.

In the main house we relocated the hot and cold water services into an attic room, to liberate more room downstairs for a bedroom enlargement.

DualStream No 1 in attic room

The other DualStream was sited in the annexe.

DualStream unvented No2 in annexe

The whole system was powered by a new Grant 36-46Kw Vortex condensing oil boiler (with a 3yr warranty) located in the garage.

Grant Vortex condensing oil boiler in the garage

We then converted every radiator to Hometronic using the HR80 valve; 

Hometronic radiator valve - remote control your heating!

this, combined with the Hometronic Manager controller, gave our customer the ability to control the heating in the house in 16 completely addressable zones.

Dean commissioning the new Hometronic system

In addition, they can also control the hot water storage cylinders independently, all from the Hometronic Manager (see picture above). 

Dean has given them ‘lifestyle buttons’ programmed to allow for guests, the entire heating map and hot water provision can be changed to accommodate any scenario with one simple button press.

Every room in the house is now thermostatically controlled, and the boiler only fires when necessary.  You won’t read about this system under ‘energy saving’  in Good Housekeeping;  we are years ahead of the game in energy conservation.

Outwood, Surrey

Our customer, in Outwood, Surrey, owns a large house that has recently been comprehensively extended.

In 2006 HWCH fitted a DualStream accumulator boosted unvented hot and cold water system, to make all the baths and showers deliver a hotel-type performance.  At the same time we fitted the latest Grant Vortex 46Kw oil fired condensing boiler plant in the cellar.

In 2008, following the building extension works,  we were invited back to upgrade the installation with our Hometronic domestic heating controls.  This innovative product allows our customer to divide his property into 16 separate zones of heating, each individually monitored and controlled by radio links.

The Hometronic controller was fitted in a utility room, out of the way. 

Hometronic Controller Outwood 2008

From this unit the customer has full control of all 16 areas, plus hot water timings.  As there are usually only three occupants to the house (which now includes a granny annexe), the heating levels can be phased during the day to follow the occupants, rather than heating the house in its’ entirety.

Radiators adapted to Hometronic - Rear Hallway

In fact, up to 1600 different temperature set points can be programmed in for a week.  No customer has yet managed to schedule that many changes!

All radiators are adapted to take the Hometronic hardware, even the towel rails, which can now be scheduled to warm up in the summer!  On their own!  No pipework or flooring adaptations are usually needed.

A towel rail being adapted for Hometronic, warm towels in the summer!

At the same time we made a few alterations while the system was being converted.  Here is a radiator being added to a previously unheated WC.

While we were there, we added a radiator in one of the WCs. Much more comfortable.

Finally, the system HWCH installed in the cellar back in 2006 was updated by our in house electrical specialist, and the system was filled with Fernox inhibitor and tested.

Dualstream OSO 500/300 litre and Grant Vortex condensing oil boiler

Our customer will now have warmer rooms when and where he wants them, whilst saving energy everywhere else in the property.  We believe Hometronic is the future for heating larger houses….