Strange boiler / immersion /pipe noises

[SwitchTheElectricsOff]

Morning all

I wonder if someone can help me. I'm at my elderly inlaws house and have noticed their heating system is making very loud knocking/gurgling/very strange noises when the heating is on.

I think their heater is an Ideal HE35, so pretty old. Their thermostat (Honywell HWC80) keeps flashing a red light, so I've changed batteries and that now appears to be working - in a fashion.. It seems even when the temperature has been reached, the boiler just keeps on heating the rads.

The inlaws usually have the boiler set to constant via another Honywell timer controller and use the thermostat to adjust, but last night the noise became so bad I decided to switch the heating off.

At first I thought it may be an airlock between the boiler and immersion, but some of the noises don't point to air (knocking/tapping/screeching/moaning), it's almost as if the heating system has a very bad case of indigestion!

 

[SwitchTheElectricsOff]

An update (if anyone can help)

I've re-bonded the thermostat to the receiver (thermostat is in the hallway, receiver is in the airing cupboard beside the immersion.

The heater now clicks on as/when.

I've checked the loft tanks, there are three - two large sealed cold water, and a small expansion, filled 3/4 up. Looks reasonably clean.

The gurgling/banging/moaning is coming from the pipes in the wall.

Now, I've discovered the 3 way honeywell motorized valve for the water/CH has burnt out, I've taken the head off to double check. It's dead. The valve head was quite sticky, so I've taken a spanner to it to loosen (read instructions about how many degrees it is limited to). The head I've twisted to it's almost 50/50 between water and CH

So far, they have hot water and the rads are hot(ish). The immersion was set to 20 degrees for some reason, I've put this to 50 degrees. Since doing this, they've had no noises at all.

I'm planning on getting the valve fully replaced figuring if the head has gone, the ball inside is probably on its way out too.

In the meantime I'm trying to understand why the immersion was set on 20 degrees, and how that works heating the water/taps?

 

[SwitchTheElectricsOff]

Another update

I've discovered the hot water pump (grunsfoss) isn't pumping the water to the CH, the only way I can get it to come on is by turning the immersion heater up

Any suggestions?

 

[endecotp]

Is it an immersion heater or a cylinder thermostat?

 

[SwitchTheElectricsOff]

Good morning

This is the setup as I got a few details wrong:

Downstairs (literally under the stairs... in a ridiculous position):
Ideal ICOS HE24

Hallway:
Honeywell HCW80 thermostat

Upstairs cupboard:
Generic immersion heater & Honeywell L641A1039 Cylinder Thermostat (or similiar)
Honeywell 3 way motorized valve V4073A (4 wire type)
Honeywell HC60NG receiver
Grunsfoss pump (pointing downwards towards the motorized valve)

Loft:
2 x large water tanks
1 x expansion tank

I've downloaded all the user and installation manuals and studied them (need to get out a bit more...)

I took the 3 way valve head off and out of the receiver unit to open up and check, worked out pretty quickly it was dead - the arm had no tension and the gears looked worn.

I re-added the valve head back to the receiver unit, thinking there must be some kind of command it sends to the pump about it turning, so have left it dangling by the lead from the Honeywell receiver, none of the gears are moving, but I do hear it trying to do something. I've manually adjusted the actuator(?) to about half way, so they were getting hot water and central heating.

It was working fine for a while, then the pump decided to stop pumping. I can see the thermostat talking to the receiver, and can hear the motorized valve trying to turn, but the pump won't come on with the rest of the kit.

The only way I can get the pump to work at the moment is to higher the heater setting on the immersion heater thermostat, and then it fires up quite happily heating the CH (so am assuming the motorized valve sends a command for it to start?). After a while the pump stops again, so I assume the cylinder thermostat has reached the temperature. During all this the boiler is idly sitting there not burning waiting for a command.

I've done so much searching and am starting to reach the end of my resourcefulness(!), the inlaws are in their 90's so doing everything I can to keep any costs down for them. I'm going to pop to screwfix or toolstation today to buy a replacement head in the hope it will cure the current issue starting the pump

In about 8 weeks they have a plumber coming in to install a couple of rads, so am going to ask him to change the entire valve for them, but in the meantime I just need to get it working for the short term

Thankyou for any help you may have!

Is it an immersion heater or a cylinder thermostat?

 

[dilalio]

It seems as though you are referring to the HWC (Hot Water Cylinder) as an “Immersion Heater”. The “immersion” is the heating element that allows water in the cylinder to be heated by electricity... it should normally be switched OFF and is only used in the event of a boiler/gas problem, and if the hot water runs out and more is needed quickly - as it is located at the top of the HWC and heats the water there.

As for other system issues, it is common for MV’s (motorised valves [2&3 port]) and pumps to fail over time.

If the system has not been professionally attended to for a number of years, and is in constant use by elderly occupants, it is likely that there will be a fair amount of contamination in the system water, HEX (heat exchanger) and other system components.

I would suggest...
Drain down and clean through the system water with chemical flush and refill with inhibitor (might be worth leaving out the inhibitor until plumber comes as he will drain down and lose whatever you put in - he can then refill and add inhibitor).

check performance of the valve head, valve and pump - replace as necessary: would be worth doing just as a matter of good practice and future cover against eventual failure and nuisance breakdown.

Get the boiler serviced - properly!

 

[SwitchTheElectricsOff]

Thanks for that big fella, that's exactly what I'm going to get this plumber to do - they are having a walk in shower put in by the council for free aswell as two rad installs, so I'm going to get him to replace the entire valve, flush and service the system (heck, if it's free I'll make sure they get their money's worth)

Apologies about immersion, you are right, they've got a switch labelled 'immersion' in the kitchen and not knowing much about heating intricacies, assumed the lot was called it! It's always switched off, they know if the switch is on, it costs them quite a few pennies more

I've ordered a new head from Amazon, it'll be coming tonight

Out of my own lack of knowledge, why does the pump currently come on with the HWC thermostat turned up, and not when the hallway thermostat calls it? It was working fine before I took the valve head of - Does the motor unit send a command it's drawing water to the CH?

Later on in the year I'll be studying plumbing, so it's all good experience!

It seems as though you are referring to the HWC (Hot Water Cylinder) as an “Immersion Heater”. The “immersion” is the heating element that allows water in the cylinder to be heated by electricity... it should normally be switched OFF and is only used in the event of a boiler/gas problem, and if the hot water runs out and more is needed quickly - as it is located at the top of the HWC and heats the water there.

As for other system issues, it is common for MV’s (motorised valves [2&3 port]) and pumps to fail over time.

If the system has not been professionally attended to for a number of years, and is in constant use by elderly occupants, it is likely that there will be a fair amount of contamination in the system water, HEX (heat exchanger) and other system components.

I would suggest...
Drain down and clean through the system water with chemical flush and refill with inhibitor (might be worth leaving out the inhibitor until plumber comes as he will drain down and lose whatever you put in - he can then refill and add inhibitor).

check performance of the valve head, valve and pump - replace as necessary: would be worth doing just as a matter of good practice and future cover against eventual failure and nuisance breakdown.

Get the boiler serviced - properly!

 

[dilalio]

Out of my own lack of knowledge, why does the pump currently come on with the HWC thermostat turned up, and not when the hallway thermostat calls it? It was working fine before I took the valve head of - Does the motor unit send a command it's drawing water to the CH?

 

[Mottie]

I may be wrong (and I’m sure I’ll be corrected if I am!) but the way I understand it is that when you turn up either the hwc or room thermostats, that then activates the valve. When the valve opens fully, that then sends a signal to the boiler to fire up and the pump to start running. Maybe your boiler/pump isn’t getting the signal from your valve?

 

[SwitchTheElectricsOff]

Thankyou for that, lots of electrikery going on!

That explains why the pump isn't being activated then

Just spoke with the oldies, seems it hasn't been working for a ...... month... They've been using their electric heater

Sometimes it's easier just to bite my tongue and smile

 

[SwitchTheElectricsOff]

I've been messing with the motor this morning, thinking it might have been a mechanical side to the pump call where I could wedge something in until the part arrives, but now understanding from the video dilalio kindly found and posted, I now know different

It's amazing how all these little bits of kit link and work, I'm not surprised they just give up the ghost!

I may be wrong (and I’m sure I’ll be corrected if I am!) but the way I understand it is that when you turn up either the hwc or room thermostats, that then activates the valve. When the valve opens fully, that then sends a signal to the boiler to fire up and the pump to start running. Maybe your boiler/pump isn’t getting the signal from your valve?

 

[dilalio]

Yes, it’s true, MV’s are electro-mechanical devices that move thousands of times throughout their operational lifespan and will therefore eventually fail through wear and tear!

Still beats having to remember to manually operate a valve to put the heating on though

 

[SwitchTheElectricsOff]

Good news, I think

I've installed the replacement 3 way motor valve, the thermostat clicks in the receiver, the pump comes on, boiler kicks in and rads get hot. The hot water is hot so all good there

The motor box head is really really hot, I opened it up to have a nose and can see the brass claw touching the little black switches, completing the circuit, but, when I switch the CH off via the kitchen wall comtrol or the receiver unit, the motor isn't reversing to unclick that link, so the circuit is effectively on all the time?

What should the motor be doing when the CH goes off? I'd have thought it would reverse to un touch the little switches?

Yes, it’s true, MV’s are electro-mechanical devices that move thousands of times throughout their operational lifespan and will therefore eventually fail through wear and tear!

Still beats having to remember to manually operate a valve to put the heating on though

 

[heatservice]

The motor will (spring) return to the hot water position (unpowered) only when there is a demand for HW, but will sit there in the heating position even after heating has gone off. The manufacturers re- configured the wiring around 30 years ago, prior to then these valves returned to the unpowered position if there was no demand, It's called built in obsolesance as they realized that if the motor sat all night powered up it life would be much shorter, there is no good reason for it, I did ask Honeywell at the time why they had done it, their answer was it saves time when the valve moves from HW only to Heating only position, which must be every bit of 4 seconds.

 

[SwitchTheElectricsOff]

Thankyou for that - It seems quite counter intuitive!

So even when the CH is off, the gears inside will stay connected to the microswitches by default, until the time comes for HW to be on (but CH off?) and then it will spring back? In which case, what happens when the CH is on, and there is demand for HW?

I did try that earlier on, but the gears firmly stayed in place, maybe I didn't give it enough time? What should the system be for it to force back to test?

Admittedly I did slide the manual leaver when I first installed it without realising, and it hasn't sprung back yet to auto

The motor will (spring) return to the hot water position (unpowered) only when there is a demand for HW, but will sit there in the heating position even after heating has gone off. The manufacturers re- configured the wiring around 30 years ago, prior to then these valves returned to the unpowered position if there was no demand, It's called built in obsolesance as they realized that if the motor sat all night powered up it life would be much shorter, there is no good reason for it, I did ask Honeywell at the time why they had done it, their answer was it saves time when the valve moves from HW only to Heating only position, which must be every bit of 4 seconds.