Heating Staying On With Hot Water

A customer asked me to look at their heating as the radiators had been coming on whenever the hot water was heating. Sure enough the heating was a three-port motorised valve system and had the ACL Drayton Lifestyle valve that pre-dated the latest MA1 version.

Unlike the MA1 version the earlier one does not have a "snap-on" actuator. For this reason it was difficult to discover whether the spindle was seized or the synchron motor. It was late on a Friday when I looked at the job and wasn't going to be cold, so I opened the actuator, removed the sychron motor and forced the mechanism to the hot water only position. This kept the hot water working correctly until I was able to return and replace the motorised valve.

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.

Glow-worm 30 CXi Flue Sampling Point Cap 0020031334

I went to issue a Landlord's Gas Safety Certificate at a property which had a Glow-worm 30 CXi fitted. I stripped down the boiler for a service and as I did so noticed that the cap which usually covers the flue probe hole was sitting on top of the boiler. At first I assumed that the previous engineer had forgot to replace it. I tried to thread the cap back on but it was not screwing on. Looking at the plastic cap it had started to degrade, the threads were worn away and the condition of the plastic was deteriorating. The thread on the flue which the cap screws onto looked to be in good condition.

The boiler is the older version which had an earlier Vaillant flue terminal. The flue sampling point is on the bend of the elbow unlike the equivalent Vallaint combination boiler which has a separate flue adaptor on top of the boiler with an inner and outer flue sampling point and different caps with different threads.

I asked in Parts Center regarding this part and was given a retail price of £53+VAT and told they only come in packs of five. The part number is 0020031334. The going rate appears to be around £40+VAT online, but our price at Parts Center was £30.10+VAT which is still a lot for 5 plastic caps and washers. For a critical safety item to have failed at this boilers age is not good and these new ones I hope are better made. There is a Technical Bulletin which covers this issue, number 138.

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.

Heating Coming On With The Hot Water

I had to look at a system where the heating was coming on with the hot water even though the heating was turned off and down. The system was a three-port motorised valve set up and had a Drayton MA1/679-3 valve. The valve was stuck in the middle position as I could see from indicator on the side. I removed the head from the valve body to see if the spindle had seized or it was a problem with the head. The spindle was free, but there was an unusual amount of rattling coming from the valve head. I opened the valve head and both the return springs were loose in the head. Both of the plastic lugs that the springs attached to had broken off also. I replaced the head of the valve and the system was working 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.

Jaguar Combi Boiler F1 and F3 Error

Another engineer had been to look at a Jaguar Combination boiler that was coming up with the error code F3 and not giving good hot water. He stripped out the plate heat exchanger and cleaned the dirt build up out which seemingly solved the issue.

However, the problem started occurring again and so I booked an appointment to have a look at the problem myself as the other engineer was on holiday. The next day the F3 fault had escalated to an F1 fault and the boiler was failing to light so I attended the same day. I looked at the boiler and it was a sparking but failing to light, but there was no problem with the gas supply. I realised that the F1 code was due to the overheat thermostat cutting the boiler out and not allowing the boiler to light. I reset the overheat thermostat and the boiler was able to light again.

Running the boiler for the hot water, the boiler got up to temperature quickly and cut out before the hot water was hot at the tap. The hot water would then got quite hot and then the boiler would relight as the boiler cooled down. The water would cool before the boiler could catch up. The boiler was also quite noisy suggesting that the circulation was poor. There didn't feel like there was much vibration coming from the pump. I removed the central screw on the pump to check that the spindle was free. When the boiler was running the pump was spinning but it didn't look as fast as it should be.

Fortunately the customer had a replacement pump and housing in his garage. When changing the pump I changed the fibre washer on the top connection as they don't seal very well when reused. I also had to clean the brass spindle that the pump slides onto as there was a fair amount of scale build up on it which was preventing the o-ring from making a good seal.

Replacing the pump solved the F1 and F3 errors and the boiler was running well although the hot water was still quite hot it was modulating 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.

Potterton Profile Not Lighting

Had a call to look at a Potterton Profile today which was not working properly. The customer said that the hot water was only lukewarm and the boiler was lighting but not staying lit for long, or not lighting at all. When I arrived the fan was running, but the boiler was not lit or trying to light. I reset the thermostat and it lit without any trouble and continued to run. I reset the thermostat a couple of times and again it lit and ran as it should. I opened the case and looked inside the boiler but there didn't look as if there was any issues. I checked the burner pressure which was correct. I lowered the controls cover and made sure that the air pressure switch tubes were connected properly and not kinked. All of the electrical connections looked good to.

I put the boiler back together and as I was screwing the screw that holds the grey bottom cover on it started playing up. The boiler was running but cut out and the fan continued to run but did not try to light. As I moved the screw the boiler was cutting in and out, making a sort of juddering noise. The customer said it had been making this noise for months and assumed it was limescale. I lowered the controls cover again to and the boiler cut out again, moving the connections to the PCB I could see a small spark due to a poor connection. There was a dry joint on the longer multi plug at the connection of the brown wire. The brown wire connects to the air pressure switch which explains why the boiler was not always trying to fire when the fa n was running. I replaced the PCB to solve the problem.

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.

Boilermate II Tripping Electrics

I received a call from a customer to say that his fusebox kept tripping out when the heating and hot water circuit was on and therefore didn't have any heating or hot water. There was also a leak in the airing cupboard.

The first thing I looked at was the airing cupboard which housed a Boilermate II. As water and electricity don't mix I assumed that the leak in the airing cupboard was related to the tripping electrics. I correctly guessed that the water was leaking from the thermal store. It is quite common for the small header tank on the top to perish and start leaking onto the top of the main cylinder, this water then runs down inside the controls cover and onto the electrics.

In this case, the leak was due to the ball valve failing. The ball valve inlet and overflow outlet were at similar heights so when the water filled to overflow there was some minor escape from the hole for the ball valve. The ball valves fitted to these thermal stores is different to the standard ball valve in that the float arm is a different length to enable you to install it through the hole in the header tank. If you are unable to purchase one swiftly you should be able to swap the float arms over by removing the split pin.

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.

Protherm 40-50 Ci No Heating Or Hot Water

I was called to look at a system with a Protherm 40-50 Ci as the customers were getting no heating or hot water. When I arrived the heating and hot water were set to be on but there was nothing happening. After sliding the bottom tray off I could see an orange glow coming from the control box so I knew that the boiler was receiving power. The overheat reset button had not popped out on the front of the control box.

I asked the customer if the boiler had been behaving itself over the last week,and they said that it had been getting noisier. They described the noise as a loud whining. I opened the case and checked for power to the fan, which there was but it was not spinning. I replaced the fan and the boiler was working quietly and correctly 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.