Looking for advice on boiler control.

[rwiddowson]

Hello.

I have an old Potterton Netaheat MkIIF and am considering getting it changed though money is extremely tight in the current climate.

I went on the Energy Savings Trust website earlier as I am considering fitting a room thermostat.

I still have the original manual for the Netaheat. It was installed around 1983/1984 from memory.

I am concerned at the increasing gas prices and am looking to invest a little amount of money now whilst I take advice on a boiler replacement. I have been dwelling on changing the boiler for years and am reluctant because it never breaks down.

All of my family, friends and neighbours that have had new boilers fitted have had nothing but breakdowns.

That aside, I am considering a wireless room thermostat (even though I detest wireless - nothing so sure as a wire!).

I assume my boiler cycles on and off constantly as I doubt it is wired to do otherwise. I understand that this is called Boiler Interlock. Not even sure if this is possible on an old Netaheat.

If it is and any knows, I would appreciate any good advice.

I understand that if I have a room thermostat, if wired in correctly, I can turn the boiler up and allow the thermostat to do its job.

I have a big old Victorian house and it is costing iro £200 a month to heat only 5 rooms whilst the majority of the house remains stone cold!

 

[D_Hailsham]

I have an old Potterton Netaheat MkIIF ... I am considering a wireless room thermostat

Why wireless?

I assume my boiler cycles on and off constantly as I doubt it is wired to do otherwise. I understand that this is called Boiler Interlock. Not even sure if this is possible on an old Netaheat.

I assume that you do not have a room thermostat at the moment. In that case, the boiler will be turned on and off by the thermostat built into the boiler, which just controls the water temperature. An interlock is an external control which turns the boiler on and off according to the room temperature.

I understand that if I have a room thermostat, if wired in correctly, I can turn the boiler up and allow the thermostat to do its job.

Correct. A room thermostat will also help reduce your large gas bills.

I have a big old Victorian house and it is costing iro £200 a month to heat only 5 rooms whilst the majority of the house remains stone cold!

But you are still partly heating the rest of the house as you cannot completely insulate the five heated rooms, so heat escapes from them.

It would be helpful to know what time controls you have for the heating and hot water systems.

 

[rwiddowson]

Thanks for the fast reply.

Wireless (even though I detest it) because it is simple and I do not want to create work unnecessarily as I tend to always have 'a lot on my plate'.

I have a wireless alarm on the house and it goes off no end of times false alarm or RF trouble.

I suppose I could throw a cable up into the loft and across and down but I have nice alcoves and I do not want to butcher them. The nice thing is that it would be a lot cheaper for a wired one and there is nothing to go wrong compared to a wireless.

I am prone to rushing jobs!

I have no room thermostat at the moment and should have thought about putting a thermostat in years ago but what is gone is gone.

So a room thermostat would act as the interlock then from what you are saying?

I currently have an EP6002 Programmer installed which I did a few years ago because the old EP2002 stopped working through water trickling down the walls onto it when I had to change the CH pump.

I am pretty sure it will allow a thermostat to be wired into it.

I know exactly what you are saying about heat loss through semi-exposed walls and thermal transmission.


I should really consider having the outside inside but a lot of firms that do it are cack-handed when it comes to detailing IMHO and you lose any architectural features too.

 

[D_Hailsham]

Wireless (even though I detest it) because it is simple and I do not want to create work unnecessarily.

Wireless it is then.

So a room thermostat would act as the interlock then from what you are saying?

Correct

I currently have an EP6002 Programmer installed which I did a few years ago because the old EP2002 stopped working through water trickling down the walls onto it when I had to change the CH pump. I am pretty sure it will allow a thermostat to be wired into it.

It's essentially a case of inserting the wireless receiver into the line from the EP6002 to the boiler.

The receiver should be mounted near the boiler (see installation instructions) where it can also pick up a permanent mains supply. (This is to power the receiver)

When you have chosen your stat (A good reliable wireless model is the Honeywell DT92E.) come back and we can advise on wiring.

It's essential to check that there is reliable communication between the transmitter and receiver before fixing them in place.

 

[Agile]

You sound like an ideal candidate to have a new boiler and proper controls fitted under the Green Deal

Tony Glazier

 

[JonCa]

You sound like an ideal candidate to have a new boiler and proper controls fitted under the Green Deal

Whilst an apparently ideal candidate, and perhaps Green Deal things have moved on a bit, but when first launched there did seem to be lots of questions around the real costs. Initial survey, seems big boys do the work and companies such as BG are not especially known for their reasonable charges. Concerns over tying the loan to the house come resale time.

If its a big house with only a few rooms getting warm it sounds like a basic check over could help in the short term. Things you can probably do yourself like bleed rads, check balancing (cos if lock shields are shut down to much you just wont get out what the boilers putting in). Also if flow is to restricted then the boiler return is always cold so boiler burns for 99% of the timers ON time.

While you can tweak the old one
Long term a new boiler with appropriate controls will be more economic on gas consumption.

 

[rwiddowson]

Thanks for the great advice.

I had not looked into any grant type schemes and have had a quick read up on the Green Deal initiative.

Thing is being stuck with a company that may overcharge for the works is really not appealing to me. I would rather the money go to a reasonably priced genuine plumber that has mouths to feed rather than corporate pockets.

I have enough equity in my house to do anything I want in reality. It is nearly paid off at 44 years old and I do not like the thought of being entrenched in more debt for another 20 years.

I'll try and take a look at some controls over the weekend.

One problem in the back of my mind is with wireless, we have a wireless alarm and it is hopeless. The control panel for it is near the front bedroom.

This is some 13 metres forward to where the boiler sits downstairs and I wonder if the signal will be strong enough. Also, what would happen if the wireless signal drops? Would anyone happen to know if it simply defaults to normal operation?

 

[D_Hailsham]

One problem in the back of my mind is with wireless, we have a wireless alarm and it is hopeless. The control panel for it is near the front bedroom.

Do you know which frequency band the alarm uses?

This is some 13 metres forward to where the boiler sits downstairs and I wonder if the signal will be strong enough. Also, what would happen if the wireless signal drops? Would anyone happen to know if it simply defaults to normal operation?

It will depend on what is between the transmitter and receiver. 13m of open air will have no effect. But if you have a couple of 2ft thick solid walls in the way the signal will get attenuated a lot.

Of course you don't have to mount the receiver right next to the boiler, which is why I suggested checking the signal strength before fixing anything to the wall. This is easily done by connecting a long power cable (so you can move the receiver about) with a plug on one end to the L and N terminals of the receiver. Then follow the signal checking instructions in the Installation Manual. If it's no good you should have no problem getting your money back as it is 'not fit for purpose'.

Honeywell wireless products are normally OK.

 

[rwiddowson]

Do you know which frequency band the alarm uses?

433MHz from memory.

Of course you don't have to mount the receiver right next to the boiler, which is why I suggested checking the signal strength before fixing anything to the wall. This is easily done by connecting a long power cable (so you can move the receiver about) with a plug on one end to the L and N terminals of the receiver. Then follow the signal checking instructions in the Installation Manual. If it's no good you should have no problem getting your money back as it is 'not fit for purpose'.

Honeywell wireless products are normally OK.

Nice bit of lateral thinking that. I can simply mount it upstairs along the corridor and into the back bedroom.

Interesting turn up for the books. Just been to see a mate for a cup of tea and mentioned I was thinking about fitting a thermostat.

He did nothing other than open his office draw and give me a Sunvic TLX 7506 and TLX 1206 Receiver.

BINGO!

 

[D_Hailsham]

Do you know which frequency band the alarm uses?

433MHz from memory.

You shouldn't get interference problems from wireless stats which operate in the same band, however many modern wireless stats now operate in the 800MHz band, so they couldn't cause a problem

Just been to see a mate for a cup of tea and mentioned I was thinking about fitting a thermostat. He did nothing other than open his office draw and give me a Sunvic TLX 7506 and TLX 1206 Receiver. BINGO!

Didn't you wonder, just a teeny bit, why it was in his drawer and not on his wall? And what stat is he now using?

Hint: do a search for Sunvic on any forum.

 

[rwiddowson]

I have checked with him and he doesn't have ANY fitted.

I thought he wouldn't because he is so anal about detail.

Anytime I ever ask him if him and his wife are free at the weekend, he is nearly always bloody painting! Unless he uses that as a euphemism?

 

[JonCa]

Interference with 868MHz should be very low, I believe that all are digital in that any signals carried include an identifying message id so that interference should not occur. End user terminology that relates to this is "bonding" where the two ends are configured for who they will communicate with. Signals/messages/instructions are very short duration generally milliseconds. So as mentioned it really is more about making sure you have suitable signal coverage and most devices have a test mode for this.
I live in a large Victorian double fronted place (ground floor appx 180sqm) and currently use wireless Honeywell programmable stats with no signal loss issues, and they get moved around all the time.
So while I understand your wireless reservations I would suggest that they are not necessary.

 

[JonCa]

Anytime I ever ask him if him and his wife are free at the weekend, he is nearly always bloody painting! Unless he uses that as a euphemism?

Nothing wrong with euphemism(ing)

Wots painting

 

[rwiddowson]

Well. To add to the mix and let's hope that the old Sunvic does have an identifying code, there is a sticker on the rear of the receiver which states 433 MC so I assume that this is 433 MHz (the same as the alarm).

I am sure that there will be no problem with this anyway judging by what JonCa states.