Hybrid heat pumps – the way forward for our aged housing stock

Some background

Many people will have heard of heat pumps and certainly AC – air conditioning units? Firstly a heat pump IS an air conditioning units and IS a refrigeration unit.

The function of a heat pump (the generic name for all 3) is to extract heat from one source and use it in another source. With a fridge, it’s job is to take heat from the warm air in the fridge and deposit it outside the fridge, leaving the fridge cooler. The heat pump does the same but takes heat from outside a building and sends it into a building to heat the living space.

We call this process a reversible refrigeration cycle because it uses no fuel such as oil or gas and all the energy it creates it reuses.

The process requires an electric pump (compressor) to circulate a fluid (gas and liquid) round the system from indoors to outdoors, it is this pump that requires energy in the form of electricity.

A heat pump is very efficient because it is using free heat from outside (as long as it’s above 7°c) and often has an efficiency of 500%. We call this efficiency a COP or coefficient of performance, which in essence means that for every KWh of energy consumed (in electricity) the heat pump produces 5KWhs of heat energy. Unfortunately the great drawback of heat pumps is two fold. 1) they run on electricity which is about 40p/KWh at current (June 2022) prices and 2) they are much less efficient on cold days so reducing the benefit.

So how can we use that efficiency in heating our homes? One approach is to us a gas boiler and a heat pump in tandem. The heat pump works during the cooler, spring / autumn months (6-8 months) and then the gas boiler takes over during deep winter (December and January). This is believed to reduce the gas consumption by over 80% which of course means a reducing in greenhouse gases.

This technology can be further advanced by installing a system where the electricity used is obtained for free*. If a property is capable of supporting solar panels (PV) then a good proportion of the heat pumps annual electricity usage can be supplied by a modest PV array.

The solar panels can also be linked to a battery pack that will store the electricity until it is needed, say in the early morning when the sun is still in bed! The battery pack would then charged up during the sun light hours when the heating system is switched off as the occupants would be out of the house at work, in many cases.

I am starting a project at home to link all of these technologies and will be updating my blog with progress. So far I have partly installed the buffer tank.

First progress 6th June 2022

Heat pump progress so far, 25th June 2022
Progress today (27/6), taken the flow and return outside and pressure tested the system so far.

More progress this week. Heat pump out door unit brackets fabricated and the heat pump is due to be delivered and fitted this Tuesday (2nd Aug), very excited

Another little milestone this week (4/8/22) as I manage to get the heat pump lifted and mounted on the wall outside, not easy given it’s 4m up and weighs 200kgs.

Hiab does the trick no problem
Happily mounted on the external wall waiting for the pipework and electrics to be connected up.

Pipe work now installed outside but insulation and trace heating still to do

Pipework in place ready to be tested and insulated

We had electricians install the cables and wire up the charger / inverter and the indoor and out door unit so that it’s now ready to be switched on when the pipework is complete.

With the insulation phase now completed I’m ready to connect the heat pump into my existing central heating system and wire up the electrical controls so that heat is pumped at the right time and to the right place.

Pipes and cylinder now fully insulated to prevent heat loss
External flow
and return pipes insulated

Anti-freeze valves fully insulated to minimised heat loss

A flue too far.

This is the condition of a flue up in a loft that I found while investigating poor boiler performance. The boiler had been serviced by British Gas every year and given a clean bill of health. On closer inspection of the flue I found it was hot to the touch on the outside (the cold air intake side) which led me to believe that exhaust gases were escaping from the inner pipe and contaminating the fresh air coming into the boiler. Naturally I placed an At Risk warning notice on the boiler and switched it off.

I was asked by the customer to investigate further and found, as expected, that the internal pipework had come loose and that the boiler was burning it’s own exhaust gases, creating high levels of carbon monoxide.

I don’t know how long the flue pipes has been disconnected but I am sure the ah-hoc installation was an original feature back in 2001 when the boiler was installed.

With the flue in such poor condition and the boiler 20 years old and performing poorly the clients elected to fit a new boiler. They decided upon a Viessmann 100w system boiler linked to a 250L unvented cylinder. The system is a high tech system running on weather compensation with domestic hot water priority using the Viessmann 4 pipe system, all managed via the Viessmann, ViCare App. The boiler has a built in WiFi module so there’s no need for expensive external third party controls.

The new flue has taken a similar route to the old one but, as you can see, has been secured firmly to the building structure to give it many years of excellent performance and life.

An unvented disaster – saved!

We were asked to look at the hot water system at a big house in Gosforth and found a terrible mismatch of poorly configured and installed high pressure unvented plumbing.

Virtually none of the pipework is secured to any of the structure and the electrics are politely dangerous, never mind prone to failure.

What was called for was for a complete removal, redesign and reinstalling of the cylinders with new valves and pipework.

The two cylinders had a combined capacity of 500L but when we tested them the hot water ran out after 183L. Clearly things weren’t right and so we set about proposing a complete removal and reinstall.

With the clients at home more often now due to the lockdown we needed to ensure they had heating and hot water at the end of each day. Consequently we organised to remove one cylinder at a time and replumb it while leaving the other cylinder able to keep the bathrooms going.

Having removed the left hand cylinder it was possible to built a proper level base and start rerouting the pipework around the walls and down the back so that they could be effectively supported to prolong their service life.

The right hand cylinder was then moved to the left position to enable the repiping to continue while keeping services on in the house.

While we had access to the pipework behind the cylinder this was insulated and pressure tested before the remaining work was done to the right hand cylinder pipework which included the repositioning of the pump and electrical control box.

How the wiring centre should look 😀

This was again tested for safe operation and the right hand cylinder refitted into the very tight space!

And that’s it folks! The cylinders were plumbed to run in series so no issues with balancing the two cylinders working against each other and now that all of the pipework is firmly fixed to the walls it should last a good century or two!

Boiler Bee reaches 800 reviews

We are delighted to have reached the wonderful milestone of 800 reviews on Checkatrade.

We’ve been really luck to have very appreciative customer who’ve taken time to give us positive feedback, so thank you all 😀

It’s been a very stressful summer and as winter approaches we traditionally get much busier with breakdowns as people switch on their heating systems. As before we are committed to attending to your needs but we do ask that you maintain a safe distance so that we can work in a risk and stress free environment.

If we can embrace the governments hands, face, space guidance it would be great for everyone.

Looking forward to the end of the pandemic 😀

Busy time at Boiler Bee

It’s been a busy few months at Boiler Bee. There’s been the usual array of breakdowns and repairs needed for my regular customer, for whom I always make time; but as well as them I’ve been extending my portfolio by becoming trained on mobile coffee machines so that I can install, service and repair said machines and keep the mobile vans selling coffee (other drinks are available) to the general public.

It’s become evident that there is a great shortage of qualified gas safe engineers able to complete work on mobile coffee vans. Without boring you with the detail, the law states that any gas appliance must only be worked on by someone who is trained and competent. Any machine, such as a gas powered coffee machine, with a gas element is therefore a gas appliance and requires a gas engineer with the appropriate qualifications which are CMC and Comcat2. These are the qualifications I am seeking to obtain.

The governing body, UKLPG has issued codes of practice to allow engineers to interpret the British Standards and comply with the gas laws.

This qualification will allow me to service and maintain coffee machines as pictured above.

With the increase in street trade and mobile food vendors it’s a growing market that needs skilled people.

Once again, Derek and I look forward to being of service to the wider business community in the very near future 🐝

How we do magnetic filters

Tricky little job today for Derek. Like a lot of kitchen located combis there isn’t much space below the boiler to fit a jug sized magnetic filter and so at this house in North Shields it seemed possible to fit it in a cupboard next the the pipework boxing.

There was already an access hatch so all the was needed was to drain the system, cut into the pipes and connect the filter – simple!

The first job of draining went well and so Derek started cutting into the 22mm copper pipes. There wasn’t much room but since he’s only the size of a bee, he managed to get it done.

The next stage was to accurately mark out where the pipes would go and cut the holes and adjust the side of the kitchen cabinet to allow the pipework to come through. With that done the pipework could all be connected up and pressure tested before filling the system. Again this was tricky job as it required assembling the pipework in a specific order as it couldn’t be adjusted or tightened in situ.

The job turned out to be really neat and we then proceeded to flush the system to clear out all of the years of debris running round the rads. The boxing cover was replaced and hides away all of the pipes. The filter is a mini Worcester Bosch unit which is very well made and sits neatly behind the cupboard door.

Another great bit of team work with Derek🐝

New shirts for Boiler Bee

I am delighted to be sporting our new Boiler Bee work shirts.

The old shirts had been in circulation for about 15 years and, although they were still fine, were due a replacement.

The new shirts have been custom made by Canterbury of New Zealand and embroider by Global Image in North Shields

I hope you’ll agree they look fantastic!

A plasterer is NOT a heating engineer’s best friend (sometimes)

…and so the saga of boiler flues continues.

It’s every good heating engineers job to inspect flues. Sometimes this means getting your step ladders out with your torch in hand, inspecting what’s hidden in the loft.

Sometimes flues are more accessible but can also be at fault. Today’s job was just to service a Main water heater which is a relatively simple task. However, on inspection of the flue I found that the plasterers had left some of their product where it shouldn’t be.

Continue reading

Flues at wrong angles (again!)

We are increasingly being asked to look at boilers that have developed leakage problems from the flue joints. 9 times out of 10 we find that the clues have not been placed at the correct angle of 1.5-3.0° depending on manufacturer and so condensate liquid (carbonic acid) collects in the seals and destroys them.

This time the faulty flue was on an Ideal iMax 60kw commercial boiler and so made the whole job a lot more complicated.

The whole flue system was replaced and then fitted at an elevation necessary to create a 2.5° fall. This meant lifting the flue terminal from its original position so that it has sufficient gradient.

The flue was then effectively supported with clamps at ensure there was no movement and that it stayed at the correct angle and the angle of fall checked with a laser.

Unfortunately, for the church, the second boiler’s flue has also been installed at the wrong angle and this will need replacing soon.

But for now the boilers are up and running and the church is once again a warm place to worship.

How we do….under sink plumbing

Ok, it’s hidden away behind the bottles of zing, bling, ziff and tide but best practice says that unsecured pipework will eventually leak causing superficial and possibly structural damage to walls and floors.

We were recently asked to tidy up the under sink plumbing at a property in Tynemouth, see pic below.

The original work had been carried out by the kitchen fitting company and the customer had been preoccupied with a sick child at the time and so didn’t challenge the workmanship.

The hanging pipework places stresses on the joints and on the flexible hoses that connect to the kitchen tap. That stress exacerbates the strain on the pipe materials and significantly shorten the life of the components. A failure of these pipe would be catastrophic as they carry mains hot and cold water. After a few minutes the kitchen could be flooded.

By securing the pipe work with pipe clips it takes all of the stress away from the pipes and allows the joints and materials to continue their happy lives for many years.

The back of the kitchen units is usually very poor quality hard board and not strong enough to hold a pipe clip. Therefore a section of 12mm ply is glued to the hardboard thereby making a solid surface on which to mount pipe clips. The photo below shows this in place along with the pipework neatly cut to the correct length and the correct fitting used to connect the flexible taps hoses.

We can now be confident that the integrity of the pipework will not be compromised by poor fitting and know that this will last a life time!