Glowworm CXi Leaking Hot Water Flow Sensor 2000801910

Was called to look at a Glow-worm CXi today because there was water leaking from the bottom of it. Looking at the boiler it was difficult to see where the leak was coming from. I could see water dripping from the bottom of the boiler near the right hand side of the plate heat exchanger. Looking from side I could see the connections to the plate heat exchanger and there was no sign of water there. It was not coming from the rear of the pump housing either. It looked to be coming from between the filling loop and the pump housing. Then I caught sight of a drip, it was coming from the hot water flow sensor's connection to the pump housing.

I stripped out the flow sensor by removing the filling loop connection and inlet filter, and disconnecting the cold inlet pipe. I suspected that the o-ring may have failed or that the pump housing had split. The o-ring looked good, but there was what looked like limescale coating the flow sensor and so assuming this problem began to clean it off. As I did so I noticed that the plastic had become soft and I was able to damage it quite easily with my nail and so decided to replace it with a new one.

The old one pictured above has been superseded by part number 2000801910 which is now made of black plastic and retails in Plumb Center for £106+VAT under part number 442716. A surprisingly costly part considering it's size and lack of complexity. Replacing the flow sensor solved the leak which was good, after a couple of days I noticed that there was actually a split in the old part as pictured below.

Disclaimer:

The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem.

Work should only be carried out by persons qualified and competent to do so.

Baxi Combi 80e Dead No Lights

Was called by a customer today as their Baxi Combi 80e was not working for either central heating or hot water. I expected to find that there was not enough water pressure in the boiler, but this was not the case. There was no lights lit on the front of the boiler so I checked that the fused spur was switched on and that the fuse was ok. The fuse was ok but a 13 amp fuse, so I swapped it for a 3 amp fuse.

I removed the cover on the boiler for the electrical connection and tested for power there. There was 240v across live-neutral and live-earth, and nothing untoward between earth-neutral. There was no power on the boiler side of the 2 amp fuse so this had obviously blown. Removing the PCB cover completely I could smell that the PCB had burnt out, and there was some black staining in the cover. Removing the PCB there was considerable damage to the underside of the PCB as can be seen below.

After replacing the internal fuse and PCB the boiler was working fine again

Disclaimer:

The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem.

Work should only be carried out by persons qualified and competent to do so.

Jaguar Combi Boiler F0 Error

This is a common fault on these boilers that I get called out to regularly. Customers think that there is a serious problem with the boiler and it requires an engineers attention. In reality the problem is usually caused by the pressure being too low in the central heating system.

The boiler contains a water pressure sensor which measures the pressure in the central heating system which will need to be topped up every now and again. How often it requires topping up will depend upon the system but may only be once a year. When cold the water pressure should be topped up to around 1.5 bar. If the water pressure drops to 0.5 bar or below the F0 error will be displayed and will occur if the system is drained or the pressure drops over time.

To top up you need to press the bar button which will show the current pressure in the central heating system. Then on the flexible filling loop which is usually fitted to the pipework below the boiler the cold water inlet valve needs to be opened. On the standard filling loop which came with the boiler you will need a large-headed flat screwdriver or small adjustable spanner to open the valve. On a better quality filling loop it may have a washing machine style tap. Whilst the system is filling you may need to press the bar button again because the display will revert to the system temperature. Once the water pressure is up to 1.5 bar it is important to turn the filling loop fully off, ideally disconnecting the flexible pipe to ensure the system isn't overfilled. If you do put too much water in the system you will need to drain some out to avoid causing further problems.

As soon as the water pressure gets to 0.7 bar the F0 error will be cleared and the pump may start up to help clear any air out of the boiler. If the pressure drops regularly it may be due to a leak and further attention from an engineer may be required.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.

Worcester Bosch 28 CDi II RSF Not Working Central Heating Light Flashing

I was asked to look at a Worcester Bosch 28 CDi II RSF combination boiler which was not working for either heating or hot water. When demand was made the boiler would sound as if it was going to light, but not and then the central heating light would begin to flash slowly.

When a tap was run the boiler would kick into action and I could hear the pump running. I opened the front cover and could see that the fan was running. I could also hear the air pressure switch clicking in and out when the fan stops and starts so assumed this was working correctly after testing for continuity with the fan running. There was a clunk coming from the gas valve so I assumed the PCB was telling the gas valve to open. I connected my manometer to the inlet nipple on the gas valve and could see the inlet pressure fluctuate as the gas valve sounded as if it was opening and closing. I checked the flue outside and diverting the products towards me could smell gas so new for sure that the gas valve was opening.

The only thing that was not occurring was sparking at the electrodes. The boiler was going through all the other sequences as it should and so I reckoned it was the PCB at fault. Thankfully I was quite convinced that this was the problem as the PCB wasn't exactly cheap even with our trade discount. The PCB that I removed from the boiler had the part number 8 748 300 394, but the part I was given at Plumb Center was 8 748 300 276 which is the same as one of the part numbers listed in the instruction book for the boiler. After replacing the PCB with the one given, everything was working well with the boiler.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.

Ideal Icos Not Lighting Flashing LF

I received a call from a gentleman because his boiler was not lighting at all and was flashing the letters L and F on the display. From this information I knew he had an Ideal Icos as it is a common fault on these boilers. The fault is due to flame failure either at the ignition stage or rarely whilst the boiler is running.

I fired up the boiler and it went through the lighting process but did not light, the fan ran for a while before attempting to light again. It attempted to light three ties before going back to alternating 'L' 'F' on the display.
Each time it attempted to ignite I could hear it sparking.

I took the case off the boiler and removed the fan and burner so I could look at the electrodes as it common for them to become dirty or distorted. They looked ok, but I removed them for a closer look and a quick rub down with some abrasive. I re-assembled the boiler before trying to light it again but it was still the same.

I checked the gas pressure which was fine and the pressure was dropping as the gas valve opened and so I knew that the gas valve was working ok. I switched off the gas at the isolation valve and removed the spark electrode from the combustion chamber. I then lit the boiler with the spark electrode in a position where I would be able to see the strength of the spark. When the boiler went to the ignition stage I could hear the spark being generated but there was no spark at the electrode. Either the ignition lead was faulty or there was a problem with the spark generator. There did not look to be any issues with the ignition lead and so I replaced the spark generator.

Both of my local Parts Centers had more than one in stock which makes me think that it is not uncommon for the spark generator to fail. Their part number is 498866 or the Ideal part number of 173538. The boiler was working well again after I remembered to turn the gas back on to the appliance :-).

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.

Potterton Suprima Not Lighting

A customer of our was having trouble with his Potterton Suprima not lighting. Another engineer looked at it and when it was attempting to light it would go through the ignition sequence as normal but was sparking slowly. The green light on the PCB was flahing quickly as it does during ignition but it may have only sparked once a second when the gas valve opens. He changed the ignition lead as they often break down. The original ignition leads had a red silicon sleeve and were quite vulnerable to breaking near the electrode. There is now a replacement lead which has a black 'heat shrink' style sleeving where it passes through the case and connects onto the electrode. After replacing the electrode lead the boiler was lighting well.

This was fine for about 24 hours before I was called out there and the boiler was displaying the same symptoms. The boiler was fitted with the original PCB which I replaced like-for-like. Testing the ignition the spark was occurring much more rapidly. The boiler was a little slow to cross light but checking the burner, injector and gas pressures everything was as it should be.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.

Baxi 105e Combi Lights Flashing No Hot Water

I was called by a customer who regularly calls me because his Baxi 105e Combi boiler stops working. The boiler is installed in the loft and contrary to building regulations does not have a means of fixed access which makes it impossible for the elderly gentleman to attend to the boiler.

The boiler had gone into a fault mode and one of the LED's on the front panel was flashing. The symbol above the flashing led was an upside triangle which is the pump symbol. In the manual it suggests there is an issue with circulation, which there was. The pressure gauge was showing zero pressure and hence there was not enough water in the system.

I opened the filling loop, filling the system to 1.5 bar before switching the boiler off an on to reset it. The boiler ran and I topped up the water as necessary due to the air being expelled through the automatic air vent. Once again the boiler was working well.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.

Ideal W2000 No Hot Water

Was called by a customer as their hot water was not hot. They found it was cold, so put the programmer on for an extra hour only to hear a screaming noise coming from the airing cupboard after a short while. They turned it off and called me to have a look.

I put the hot water on and the boiler fired up straight away, so I went to have a look at the pump after turning the boiler thermostat off. The pump was running although it was a little noisy due to there not being enough water in the system. I suspected that the cold feed may be blocked and I ventured up into the loft to find that there was no water in the feed and expansion cistern, as the ball valve had been tied up for some time.

I isolated the water to the cistern and replaced the ball valve in case it had been tied up because of a dripping overflow. I then filled up the system, including bleeding the iring cupboard and radiators. I had to stop the pump a couple of times to allow all the air to filter out as the system had air-locked slightly. I ran the hot water for a few minutes to ensure it was circulating well before running the central heating to make sure there were no more air-locks.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.